Statement [Table] Statement [Line Items] Document Type Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Amendment Flag Entity Filer Category Entity Common Stock, Shares Outstanding CONSOLIDATED STATEMENT OF INCOME [Abstract] Revenues Revenues, Total Revenue Interest Income and Other Interest and other income, net Interest & other income Includes operating interest income earned as part of a core business activity, equity income representing the undistributed income or loss of investments which are accounted for under the equity method of accounting, and other miscellaneous income or loss earned from core business activities. Costs and Expenses [Abstract] Expense Research & engineering Research and Development Expense, Total Research & engineering General & administrative General and Administrative Expense, Total General & administrative Income Loss from Continuing Operations Before Income Taxes Minority Interest and Income Loss from Equity Method Investments Taxes on income Consolidated taxes on income Taxes on income Profit Loss Net income Net Income Net Income Net Income Loss Attributable to Noncontrolling Interest Net Income Loss Net Income attributable to Schlumberger Net Income Earnings Per Share Basic Net Income Net Income Net Income Diluted Net Income Net Income Net Income Average shares outstanding [Abstract] Average shares outstanding: Weighted Average Number of Shares Outstanding Basic Weighted Average Number of Shares Outstanding, Basic, Total Basic Assuming dilution Assuming dilution Assuming dilution CONSOLIDATED BALANCE SHEET [Abstract] Assets [Abstract] ASSETS ASSETS Assets Current [Abstract] Current Assets Cash Cash Short-term investments Short-term Investments, Total Short-term investments Receivables, Net, Current Receivables, Net, Current, Total Receivables less allowance for doubtful accounts (2011 - $182; 2010 - $185) Inventories Inventories Deferred Tax Assets Net Current Deferred Tax Assets, Net, Current, Total Deferred taxes Other Assets Current Other current assets Assets Current Assets, Current, Total Fixed Income Investments, held to maturity Fixed income investments, held to maturity Fixed Income Investments, held to maturity Investments in Affiliated Companies Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total Investments in Affiliated Companies Fixed Assets less accumulated depreciation Property, Plant and Equipment, Net, Ending Balance Property, Plant and Equipment, Net, Beginning Balance Fixed assets less accumulated depreciation Multiclient Seismic Data Balance at September 30, 2011 Balance at December 31, 2010 Multiclient seismic data Capitalized costs directly incurred in acquiring and processing of seismic surveys that are licensed on a nonexclusive basis, net of amortization. Goodwill Balance at September 30, 2011 Balance at January 1, 2011 Net Book Value Intangible Assets Intangible Assets, Net (Excluding Goodwill), Total Other Assets Noncurrent Other Assets Assets Assets Assets, Total Liabilities and Stockholders Equity [Abstract] LIABILITIES AND EQUITY Liabilities Current [Abstract] Current Liabilities Accounts Payable and Accrued Liabilities Current Accounts payable and accrued liabilities Accounts payable and accrued liabilities Estimated liability for taxes on income Estimated liability for taxes on income Long-term debt-current portion Commercial paper borrowings Long-term Debt, Current Maturities, Total Long-term debt - current portion Short-term borrowings Short-term Borrowings, Total Short-term borrowings Liabilities Current Liabilities, Current, Total Other Long-term Debt, Noncurrent Other Long-term Debt, Noncurrent, Total Long-term Debt Postretirement Benefits Postretirement Benefits Deferred Tax Liabilities Noncurrent Deferred Taxes Deferred Taxes Other Liabilities Noncurrent Other Liabilities Liabilities Liabilities, Total Liabilities, Total Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract] Equity Common stock Common Stock, Value, Issued, Total Common stock Treasury Stock Value Treasury stock Retained Earnings Accumulated Deficit Retained earnings Accumulated other comprehensive loss Accumulated other comprehensive loss Stockholders Equity Schlumberger stockholders' equity Minority Interest Noncontrolling interests Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Ending Balance Beginning Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Total Liabilities And Stockholders Equity Liabilities and stockholders equity, Total Receivables, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current, Ending Balance Allowance for Doubtful Accounts Receivable, Current, Beginning Balance Allowance for doubtful accounts on receivable CONSOLIDATED STATEMENT OF CASH FLOWS [Abstract] Net Cash Provided by Used in Operating Activities [Abstract] Cash flows from operating activities: Adjustments to reconcile net income to cash provided by operating activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization, Total Depreciation and amortization Income Loss From Equity Method Investments Net of Dividends or Distributions Earnings of companies carried at equity, less dividends received Income (Loss) from Equity Method Investments, Net of Dividends or Distributions, Total Earnings of companies carried at equity, less dividends received Deferred income taxes Deferred income taxes Deferred income taxes Stock-based compensation expense Share-based Compensation, Total Stock-based compensation expense Pension and other postretirement benefits expense Pension and other postretirement benefits expense Increase (Decrease) in Pension and Postretirement Obligations, Total Pension and other postretirement benefits expense Pension and Other Postretirement Benefit Contributions Pension and other postretirement benefits funding Pension and other postretirement benefits funding Increase Decrease in Operating Capital [Abstract] Change in assets and liabilities: Increase Decrease in Receivables Increase in receivables Increase (Decrease) in Receivables, Total (Increase) decrease in receivables Increase Decrease in Inventories Increase in inventories Increase (Decrease) in Inventories, Total Increase in inventories Increase Decrease in accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities, Total Increase (decrease) in accounts payable and accrued liabilities Increase Decrease in Other Operating Capital Net Net Cash Provided by Used in Operating Activities NET CASH PROVIDED BY OPERATING ACTIVITIES Net Cash Provided by Used in Investing Activities [Abstract] Cash flows from investing activities: Payments to Acquire Property Plant And Equipment Capital expenditures Capital expenditures Payments to Acquire Property, Plant, and Equipment, Total Capital expenditures Payments for Proceeds from Capitalized Costs Support Equipment and Facilities Multiclient seismic data capitalized Multiclient seismic data capitalized The net cash outflow from capitalized costs directly incurred in acquiring and processing of seismic surveys that are licensed on a nonexclusive basis. Other Payments to Acquire Businesses Payments for Proceeds from Investments Payments for Proceeds from Other Investing Activities Other Other Other Net Cash Provided by Used in Investing Activities NET CASH USED IN INVESTING ACTIVITIES Net Cash Provided by Used in Financing Activities [Abstract] Cash flows from financing activities: Payments of Dividends Dividends paid Payments of Dividends, Total Dividends paid Proceeds from employee stock purchase plan Proceeds from employee stock purchase plan Proceeds from exercise of stock options Proceeds from exercise of stock options Payments for Repurchase of Equity Stock repurchase program Payments for Repurchase of Equity, Total Stock repurchase program Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt, Total Proceeds from issuance of long-term debt Repayments of Long Term Debt Repayment of long-term debt Repayments of Long-term Debt, Total Repayment of long-term debt Net Cash Provided by Used in Financing Activities NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES Cash and Cash Equivalents Period Increase Decrease Net (decrease) increase in cash before translation effect Net increase (decrease) increase in cash before translation effect Translation effect on cash Effect of Exchange Rate on Cash and Cash Equivalents, Total Translation effect on cash Cash and Cash Equivalents at Carrying Value Cash, end of period Cash, beginning of period Cash and Cash Equivalents, at Carrying Value, Total CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY [Abstract] Statement, Equity Components [Axis] Equity Component [Domain] Common Stock [Member] Common Stock Issued Treasury Stock [Member] Common Stock In Treasury Retained Earnings [Member] Retained Earnings Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Loss Noncontrolling Interests [Member] Noncontrolling Interests Currency translation adjustments Currency translation adjustments Other Comprehensive Income, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Total Currency translation adjustments Changes in fair value of derivatives Changes in fair value of derivatives Other Comprehensive Income, Derivatives Qualifying as Hedges, Net of Tax, Total Changes in fair value of derivatives Deferred employee benefits liabilities Other Comprehensive Income, Defined Benefit Plans Adjustment, Net of Tax, Total Deferred employee benefits liabilities Comprehensive Income Net of Tax Including Portion Attributable to Noncontrolling Interest Total comprehensive income Stock Issued During Period Value Stock Options Exercised Shares sold to optionees, less shares exchanged Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Vesting of restricted stock Stock Issued During Period Value Employee Stock Purchase Plan Shares issued under employee stock purchase plan Treasury Stock Value Acquired, Cost Method Stock repurchase program Stock Issued During Period, Value, Share-based Compensation Stock-based compensation cost Stock Issued During Period, Value, Conversion of Convertible Securities Shares issued on conversion of debentures Stockholders' Equity, Other Other Dividends, Cash Dividends declared (2011 - $0.75; 2010 - $0.63) Dividends, Cash, Total Stock Issued During Period, Shares, Stock Options Exercised Shares sold to optionees, less shares exchanged, in shares Stock Issued During Period, Shares, Employee Stock Purchase Plans Shares issued under employee stock purchase plan, in shares Treasury Stock, Shares, Acquired Stock repurchase program, in shares Dividends declared, per share Dividends declared, per share Restructuring and Related Activities Disclosure [Text Block] Charges and Credits Inventory Disclosure [Text Block] Inventory Property, Plant and Equipment Disclosure [Text Block] Fixed Assets Multiclient Seismic Data [Text Block] Multiclient Seismic Data Disclosure of the carrying amount of multiclient seismic data based on completed and in-process seismic surveys. Intangible Assets Disclosure [Text Block] Intangible Assets Derivative Instruments and Hedging Activities Disclosure [Text Block] Derivative Instruments and Hedging Activities Long-term Debt [Text Block] Long-term Debt Income Tax Disclosure [Text Block] Income Tax Segment Reporting Disclosure [Text Block] Segment Information Pension and Other Postretirement Benefits Disclosure [Text Block] Pension and Other Postretirement Benefits Property, Plant and Equipment [Table Text Block] Property, Plant and Equipment Schedule of Goodwill [Table Text Block] Schedule of Goodwill Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Text Block] Schedule of Derivative Instruments in Statement of Financial Position, Fair Value Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Text Block] Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Text Block] Debt Instrument [Axis] Debt Instrument, Name [Domain] Type of Restructuring [Domain] Medicare Part D Subsidy [Member] Medicare Part D Subsidy [Member] Medicare Part D Subsidy. Guaranteed notes face amount Notes relating to interest rate swap Euro medium term note program Guaranteed Notes 5 Point 25 Percent Due 2013 [Member] 5.25% Guaranteed Notes due 2013 [Member] 5.25% Guaranteed Notes due 2013. Guaranteed Notes 3 Point 00 Percent Due 2013 [Member] 3.00% Guaranteed Notes due 2013 [Member] 3.00% Guaranteed Notes due 2013. Commercial Paper [Member] Debt, Other [Member] Debt, Other Schlumberger amounts attributable to [Abstract] Schlumberger amounts attributable to: Dilutive Securities Dilutive Securities, Total Assumed conversion of debentures Incremental Common Shares Attributable to Conversion of Debt Securities Incremental Common Shares Attributable to Conversion of Debt Securities, Total Assumed conversion of debentures Incremental Common Shares Attributable to Call Options and Warrants Assumed exercise of stock options Incremental Common Shares Attributable to Nonvested Shares with Forfeitable Dividends Unvested restricted stock Payments to Acquire Businesses and Interest in Affiliates Acquisitions and minority interest investments, net of cash acquired Senior Notes 8625 Due 2014 [Member] 8.625% Senior Notes due 2014 [Member] 8.625% Senior Notes due 2014. Senior Notes 600 Due 2016 [Member] 6.00% Senior Notes due 2016 [Member] 6.00% Senior Notes due 2016. Senior Notes 975 Due 2019 [Member] 9.75% Senior Notes due 2019 [Member] 9.75% Senior Notes due 2019. Tradenames [Member] Customer Relationships [Member] Finite-Lived Intangible Assets, Weighted-Average Useful Life, Total weighted-average life in years Inventory, Net [Abstract] Inventory Raw materials & field materials Inventory, Raw Materials and Supplies, Total Raw materials & field materials Work in process Work in process Finished goods Finished goods Property, Plant and Equipment, Net, by Type [Abstract] Property, Plant and Equipment Property, plant & equipment Property, Plant and Equipment, Gross, Ending Balance Property, Plant and Equipment, Gross, Beginning Balance Property, Plant and Equipment, Gross, Total Less: Accumulated depreciation Less: Accumulated depreciation Less: Accumulated depreciation Depreciation expense relating to fixed assets Depreciation, Total Change In Carrying Amount Of Multiclient Seismic Data [Abstract] Multiclient Seismic Data Change in the Carrying Amount of Multiclient Seismic Data. Multiclient Seismic Data Capitalized In Period Capitalized in period Multiclient Seismic Data, Capitalized in period Multiclient Seismic Data Charged To Cost of Goods Sold and Services Charged to expense Multiclient Seismic Data, Charged to cost of goods sold and services Goodwill [Roll Forward] Schedule of Goodwill Oilfield Services [Member] Oilfield Services [Member] Oilfield Services. Goodwill Translation And Purchase Accounting Adjustments Impact of changes in exchange rates Intangible Assets, Net (Excluding Goodwill) [Abstract] Gross book value and accumulated amortization of intangible assets Intangible Assets by Major Class [Axis] Intangible Assets by Major Class [Axis] Intangible Assets, Major Class Name [Domain] Intangible Assets, Major Class Name [Domain] Technology/Technical Know-How [Member] Intangible Assets Gross Excluding Goodwill Gross Book Value Intangible Assets, Gross (Excluding Goodwill) Accumulated Amortization Estimated amortization charged to income, 2011 Estimated amortization charged to income, 2012 Estimated amortization charged to income, 2012 Estimated amortization charged to income, 2013 Estimated amortization charged to income, 2013 Estimated amortization charged to income, 2014 Estimated amortization charged to income, 2014 Estimated amortization charged to income, 2015 Estimated amortization charged to income, 2015 Estimated amortization charged to income, 2016 Derivatives, by Derivative Instrument Contract [Axis] Derivatives, by Derivative Instrument Contract [Axis] Derivatives, by Derivative Instrument Contract [Domain] Derivatives, by Derivative Instrument Contract [Domain] Fixed Rate Debt [Member] Fixed Rate Debt. Floating Rate Debt [Member] Floating Rate Debt. Recognized a cumulative net gain in Equity relating to revaluation of foreign currency forward contracts and foreign currency options designated as cash flow hedges Recognized a cumulative net gain in Equity relating to revaluation of foreign currency forward contracts and foreign currency options designated as cash flow hedges Contracts outstanding in various foreign currencies (US dollar equivalent) Contracts outstanding in various foreign currencies (US dollar equivalent) Fixed Rate Debt Fixed rate debt aggregate, after taking into account the effects of the interest rate swaps Fixed rate debt Variable Rate Debt Variable rate debt aggregate, after taking into account the effects of the interest rate swaps Variable rate debt Short-term investments and Fixed income investments, held to maturity Marketable Securities, Current, Total Short-term investments and Fixed income investments, held to maturity Notional amount of interest rate swap Notional amount of interest rate swap Derivative swap interest rate Derivative swap interest rate Derivative, Fair Value, Net [Abstract] Fair values of outstanding derivative instruments Derivative Contract Type [Domain] Foreign Exchange Contract [Member] Interest Rate Contract [Member] Commodity Contract [Member] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Domain] Other Current Assets [Member] Other Current Assets. Other Assets [Member] Accounts Payable and Accrued Liabilities [Member] Accounts Payable and Accrued Liabilities. Other Liabilities [Member] Derivative Fair Value of Derivative Asset Derivative assets Derivative assets Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract] Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income Derivative Instruments, Gain (Loss) by Hedging Relationship [Axis] Hedging Relationship [Domain] Fair Value Hedging [Member] Nondesignated [Member] Derivative Instruments, Gain (Loss) by Income Statement Location [Axis] Income Statement and Other Comprehensive Income Location [Domain] Interest Expense [Member] Interest expense [Member] Gain/(loss) recognized in income Gain/(loss) recognized in income Gain (loss) reclassified from accumulated OCI into income Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total Gain (loss) reclassified from accumulated OCI into income Gain (loss) recognized in OCI Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net, Total Gain (loss) recognized in OCI Summary of Other Long-Term Debt [Abstract] Summary of Long-Term Debt Summary of Other Long-Term Debt. Long-term debt, carrying amount Long-term debt, carrying amount Fair Value Adjustment Hedging Carrying Amount Fair value adjustment-hedging Fair value adjustment, hedging, carrying amount Long-term debt, fair value Income From Continuing Operations Before Taxes Which Were Subject To U S And Non U S Income Taxes [Abstract] Income from before taxes subject to US and Non-US Income Taxes Income from Continuing Operations Before Taxes Which Were Subject to US and Non-US Income Taxes. Income (Loss) from Continuing Operations before Income Taxes, United States United States The portion of earnings (loss) from continuing operations before income taxes that is attributable to United States operations. Income (Loss) from Continuing Operations before Income Taxes, Non United States Outside United States The portion of earnings (loss) from continuing operations before income taxes that is attributable to foreign operations, which is defined as income (loss) generated from operations located outside the United States. Income (Loss) from Continuing Operations before Income Taxes and Minority Interest Income (Loss) from Continuing Operations before Income Taxes and Minority Interest, Total Income (Loss) from Continuing Operations before Income Taxes and Minority Interest Deferred Tax Assets, Net [Abstract] Components of Net Deferred Tax Assets Postretirement benefits, net Deferred Tax Assets, Intangible Assets Intangible assets Deferred Tax Assets, Intangible Assets Other, net Deferred Tax Assets, Net Deferred Tax Assets, Net, Total Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Components of Consolidated Taxes on Income Current Income Tax Expense Benefit Continuing Operations [Abstract] Current: Current Federal Tax Expense (Benefit) United States - Federal Current State and Local Tax Expense (Benefit) United States - State Current Foreign Tax Expense (Benefit) Outside United States Current Income Tax Expense (Benefit) Current Income Tax Expense (Benefit), Total Deferred Income Tax Expense Benefit Continuing Operations [Abstract] Deferred: Deferred Federal Income Tax Expense (Benefit) United States - Federal Deferred State and Local Income Tax Expense (Benefit) United States - State Deferred Foreign Income Tax Expense (Benefit) Outside United States Valuation allowance Valuation allowance Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract] Reconciliation of the US statutory federal tax rate to the consolidated effective income tax rate Non-US income taxed at different rates Effective Income Tax Rate Reconciliation, Nondeductible Expense Effective Income Tax Rate Reconciliation, Nondeductible Expense, Total Charges (See Note 2) Effective Income Tax Rate Reconciliation Other Adjustments Other Distribution [Member] Distribution [Member] Distribution. Corporate and Other [Member] Corporate and other [Member] Corporate and Other. Interest Income [Member] Interest income [Member] Charges and Credits [Member] Charges and Credits [Member] Charges And Credits. Defined Benefit Plans Disclosures, Defined Benefit Plans [Axis] Defined Benefit Plans [Domain] United States Pension Plans of US Entity Defined Benefit [Member] United States Pension Plans of US Entity Defined Benefit [Member] Foreign Pension Plans, Defined Benefit [Member] Foreign Pension Plans, Defined Benefit [Member] Service cost-benefits earned during period Service cost Interest cost on accumulated postretirement benefit obligation Interest cost on projected benefit obligation Interest cost Amortization of net loss Amortization of net loss Amortization of prior service cost Amortization of prior service cost Amortization of prior service cost Defined Benefit Plan, Net Periodic Benefit Cost before Curtailments Total Benefit cost Defined Benefit Plan, Net Periodic Benefit Cost before Curtailments Contributions to defined benefit pension plans Contributions to defined benefit pension plans Document and Entity Information [Abstract] Document and Entity Information. Schedule of Goodwill [Table] Goodwill [Line Items] Schedule of Intangible Assets by Major Class [Table] Schedule Of Intangible Assets By Major Class Table. Intangible Assets [Line Items] Intangible Assets Line Items. Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivatives, Fair Value [Line Items] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Line Items] Derivative [Table] Derivative [Line Items] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Segment Information (Textual) [Abstract] Segment Information (Textual) Segment Information. Schedule of Segment Reporting Information, by Segment [Table] Segment Reporting Information [Line Items] Earnings Per Share Reconciliation [Abstract] Reconciliation of Earnings Per Share United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] Postretirement Medical Plan [Member] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan Disclosure [Line Items] Intangible Assets Additional Information [Abstract] Intangible Assets - Additional Information Intangible Assets - Additional Information. Number of Countries in Which Company Conducts Business Number of countries in which Schlumberger conducts business Number of countries in which Schlumberger conducts business. Derivative Instruments and Hedging Activities (Textual) [Abstract] Derivative Instruments And Hedging Activities. Long-term Debt (Textual) [Abstract] Long-term Debt. Multiclient Seismic Data [Abstract] Multiclient Seismic Data. Disclosure Net Pension Cost For Parent Company Pension Plans [Abstract] Net Pension Cost for the Schlumberger Pension Plans Disclosure Net Pension Cost For The Parent Company Pension Plans. Disclosure Net Periodic Benefit Cost For The Parent Company Us Postretirement Medical Plan [Abstract] Net Periodic Benefit Cost for the Schlumberger US Postretirement Medical Plan Disclosure Net Periodic Benefit Cost For The Parent Company Us Postretirement Medical Plan. Merger Related Transaction Costs [Member] Merger and integration-related transaction costs Merger related transaction costs. Guaranteed Notes 4 Point 50 Percent Due 2014 [Member] 4.50% Guaranteed Notes due 2014 [Member] Guaranteed Notes 4 Point 50 Percent Due 2014. Guaranteed Notes 2 Point 75 Percent Due 2015 [Member] 2.75% Guaranteed Notes due 2015 [Member] Guaranteed Notes 2 Point 75 Percent Due 2015. Merger & integration Merger & integration Finite-Lived Intangible Assets, Amortization Expense Amortization expense on intangible assets excluding goodwill Price Risk Derivative Instruments not Designated as Hedging Instruments, at Fair Value, Net Price Risk Derivative Instruments Not Designated as Hedging Instruments, at Fair Value, Net, Total Commodity forward contract outstanding Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount First Quarter Employee stock options to purchase Deferred Tax Assets, Investment in Subsidiaries Investments in non-US Subsidiaries Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Basis of Presentation Earnings Per Share [Text Block] Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Text Block] Fixed Assets (Textual) [Abstract] Depreciation, Depletion and Amortization [Abstract] Estimated amortization charged to income, remainder of 2011 Future Amortization Expense, Remainder of Fiscal Year Future Amortization expense charged to income, remainder of 2011 Reservoir Characterization [Member] Reservoir Characterization [Member] Reservoir Characterization. Reservoir Production [Member] Reservoir Production [Member] Reservoir Production. Drilling [Member] Drilling [Member] Drilling. Goodwill, Allocation Adjustment Adjustments relating to Smith acquisition Segment Results [Member] Segment Results [Member] Segment Results. Other Services [Member] Eliminations and other [Member] Other Services. Revenues [Abstract] Revenue Cost of Goods and Services Sold [Abstract] Cost of Revenue: Business Acquisition Cost of Acquired Entity Shares Distributed Equivalent new Schlumberger shares of common stock issued Business Acquisition Cost Of Acquired Entity Shares Distributed. Geoservices [Member] Geoservices [Member] Geoservices. Business Acquisition, Cost of Acquired Entity, Purchase Price Business Acquisition, Cost of Acquired Entity, Purchase Price, Total Purchase price Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition [Line Items] Smith International Incorporate [Member] Smith International Incorporate [Member] Smith International Incorporate. Effective Income Tax Rate Reconciliation, State and Local Income Taxes US state income taxes Guaranteed Notes 2 Point 65 Percent Due 2016 [Member] 2.65% Guaranteed Notes due 2016 [Member] Guaranteed Notes 2 Point 65 Percent Due 2021. Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period Revenue reported by Smith Long Term Debt Additional (Textual) [Abstract] Long-term Debt Additional (Textual) [Abstract] Long Term Debt Additional. Repurchased outstanding Senior Notes due Repurchase of senior notes Repurchased outstanding Senior Notes due. Debt instrument interest rate Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Effective Percentage Effective interest rate on euro denominated debt Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities Excluded from Computation of Earnings Per Share, by Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Outstanding Stock Awards [Member] Outstanding Stock Awards [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Common Stock, Value, Outstanding Common stock equity consideration Cost of Goods and Services Sold Cost of revenue Statement, Business Segments [Axis] Segment [Domain] Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures, Total Shares granted to Directors Shares, Outstanding Ending Balance, in shares Goodwill Disclosure [Text Block] Other Intangible Assets [Member] Other [Member] Research and Development Expense [Member] Restructuring Cost and Reserve [Axis] Derivative Instrument Risk [Axis] Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest, Total Income before taxes Investment Income, Interest Interest income included in the segment results Interest Interest expense included in the segment results Interest Expense, Total Interest Derivative Asset, Fair Value, Net [Abstract] Derivative assets Derivative Liability, Fair Value, Net [Abstract] Derivative Liabilities Hedging Designation [Axis] Hedging Designation [Domain] Designated as Hedging Instrument [Member] Segment Reporting Information, Revenue Segment Reporting Information, Revenue, Total Revenue Effective income tax rate Effective income tax rate Effective income tax rate Charges and Credits [Abstract] Earnings Per Share [Abstract] Earnings per Share Acquisitions [Abstract] Business Combination Disclosure [Text Block] Acquisitions Fixed Assets [Abstract] Basis of Presentation [Abstract] Derivative Instruments and Hedging Activities [Abstract] Income Tax [Abstract] Segment Information [Abstract] Pension and Other Postretirement Benefits [Abstract] Summary of Charges [Table Text Block] Summary of Charges Summary Of Charges Table Text Block. Schedule of Earnings Per Share Reconciliation [Table Text Block] Reconciliation of Earnings Per Share Multiclient Seismic Data [Table Text Block] Multiclient Seismic Data Table Disclosure of the carrying amount of multiclient seismic data based on completed and in-process seismic surveys. Schedule of Intangible Assets by Major Class [Table Text Block] Schedule of Intangible Assets by Major Class Schedule of Intangible Assets by Major Class. Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block] Schedule of Derivative Instruments, Effect on Income and Other Comprehensive Income Schedule of Long-term Debt Instruments [Table Text Block] Long-term Debt Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Income Tax Disclosure Table Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Components of Net Deferred Tax Assets Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Components of Consolidated Income Taxes Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Reconciliation of the US Statutory Federal Tax Rate Schedule of Net Benefit Costs [Table Text Block] Net Pension Cost for the Schlumberger Pension Plans and US Postretirement Medical Plan Intersegment Elimination [Member] Eliminations [Member] Increase (Decrease) in Other Current Assets Increase in other current assets (Increase) decrease in other current assets Pension Plans, Defined Benefit [Member] Pension Plans, Defined Benefit [Member] Noncontrolling Interest, Period Increase (Decrease) Acquisition of noncontrolling interests Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Tax benefits on stock options Comprehensive Income, Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Comprehensive income Earnings Per Share, Basic and Diluted [Abstract] Earnings per Share Income Tax (Textual) [Abstract] Income Tax. Income Tax (Textual) [Abstract] Expected return on plan assets Expected return on plan assets Derivative Liability, Fair Value Derivative Liability, Fair Value, Total Derivative Liabilities Inventory [Abstract] Goodwill Long-term Debt [Abstract] Beginning Balance, in shares Goodwill [Abstract] Goodwill. Intangible Assets [Abstract] Intangible Assets. Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net [Abstract] Effect of derivative instruments in cash flow hedging relationships on income and other comprehensive income (OCI) Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Earnings Per Share, Basic [Abstract] Basic earnings per share of Schlumberger: Net Income (Loss) Available to Common Stockholders, Diluted Diluted Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest, Total Less: Income from discontinued operations (Decrease) increase in estimated liability for taxes on income (Decrease) increase in estimated liability for taxes on income Increase Decrease In Other Operating Liabilities Increase (decrease) in other liabilities Increase (Decrease) in Other Operating Liabilities, Total (Purchase) sale of investments, net Payments for (Proceeds from) Investments, Total Sale (purchase) of investments, net Donation to Parent Foundation [Member] Donation to parent foundation. Donation to Schlumberger Foundation [Member] Weighted average amortization period for all intangible assets (years) Discontinued Operations [Abstract] Discontinued Operations (Textual) [Abstract] Discontinued operations. Discontinued Operations (Textual) [Abstract] Income Tax Examination [Table] Income Tax Authority [Axis] Income Tax Authority [Domain] Domestic Country [Member] Domestic Country [Member] Foreign Country [Member] Foreign Country [Member] Income Tax Examination [Line Items] Earnings Per Share, Diluted [Abstract] Diluted earnings per share of Schlumberger: Income from Continuing Operations before taxes Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Income from Continuing Operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent, Total Income from Discontinued Operations Income (Loss) from Continuing Operations Attributable to Parent Basic Income (Loss) from Continuing Operations Attributable to Parent, Total Income from Continuing Operations Income (Loss) from Continuing Operations, Per Basic Share Basic Income (Loss) from Continuing Operations, Per Outstanding Share, Total Income from Continuing Operations Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Share, Total Income from Discontinued Operations Income (Loss) from Continuing Operations, Per Diluted Share Diluted Income from Continuing Operations Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share, Total Income from Discontinued Operations Other-net Other--net Other--net Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Discontinued Operations Payments to Acquire Businesses and Interest in Affiliates [Abstract] Acquisitions (Textual) [Abstract] Goodwill, Written off Related to Sale of Business Unit Divestiture of business Deferred Tax Assets, Operating Loss Carryforwards, Domestic Deferred tax assets, valuation allowances relating to net operating losses in certain countries Cost of Sales [Member] Cost of revenue - Oilfield Services [Member] Effective Income Tax Rate Reconciliation at U S Federal Statutory Income Tax Rate US federal statutory rate The United States federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate shall be the regular tax rate if there are alternative tax systems. Net Pretax Charges Charges, net pretax Net Pretax Charges. Schedule of Restructuring and Related Costs [Table] Restructuring Cost and Reserve [Line Items] Components of Deferred Income Taxes Deferred income taxes Components of Deferred Income Taxes. Schedule of Depreciation Expense [Table Text Block] Depreciation expense relating to fixed assets Schedule of Depreciation Expense. Schedule of Amortization Expense [Table Text Block] Amortization expense charged to income Schedule of Amortization Expense. Schedule of Inventory, Current [Table Text Block] Inventory Disclosure Net income (loss) attributable to noncontrolling interests Net income (loss) attributable to noncontrolling interests Payments to Acquire Businesses, Net of Cash Acquired Acquisition of Geoservices, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired, Total Acquisition of Geoservices, net of cash acquired Dividend payable Dividends payable Business acquisitions, net of cash acquired Other business acquisitions and investments, net of cash acquired Net decrease increase in short-term borrowings Net decrease in short-term borrowings Cash Provided by (Used in) Investing Activities, Discontinued Operations Global Connectivity Services business Discontinued Operations Cash flows from discontinued operations - investing activities Guaranteed Notes 4 Point 200 Percent Due 2021 [Member] 4.20% Guaranteed Notes due 2021 [Member] Guaranteed Notes 4 Point 200 Percent Due 2021 . Gain (Loss) on Investments Gain on investment in M-I SWACO Restructuring Charges Restructuring Charges, Total Restructuring & other Gain Loss on Investments Net of Tax Gain on investment in M-I SWACO Gain loss on investments net of tax. Other Noncash Income (Expense) Non-cash charges Cash Acquired from Acquisition Cash acquired in merger with Smith International, Inc. Stock Issued During Period, Value, Acquisitions Acquisition of Smith International Inc. Schedule of Merger Related Charges [Table Text Block] Schedule Of Merger Related Charges. Schedule Of Merger Related Charges Westerngeco First Generation Land Operation [Member] WesternGeco First Generation Land Operation [Member] Westerngeco First Generation Land Operation. Other Charges on Restructuring [Member] Other Charges on Restructuring [Member] Other Charges On Restructuring. Mexico Restructuring Charges [Member] Mexico Restructuring Charges. Mexico Restructuring Charges [Member] Repurchase of Bonds [Member] Repurchase of Bonds [Member] Repurchase Of Bonds. Merger Related Employee Benefits [Member] Merger Related Employee Benefits. Merger Related Employee Benefits [Member] Inventory Fair Value Adjustments [Member] Inventory Fair Value Adjustments. Inventory Fair Value Adjustments [Member] Notes 6 Point 50 Percent Due 2012 [Member] Notes 6 Point 50 Percent Due 2012. Notes 6.50 % Due 2012 [Member] M I SWACO [Member] M-I SWACO [Member] M I SWACO. Summary Of Charges And Credit (Textual) [Abstract] Summary Of Charges And Credit (Textual) [Abstract] Summary of charges and credit. Impairment Charges Impairment charges. Impairment charges Asset Impairment Charges Asset Impairment Charges, Total Asset Impairment Charges Repurchase Senior Notes Repurchase senior notes. Repurchase Senior Notes Acquisition [Member] Employee Severance [Member] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Impairment in Value of Asset [Member] Component of Other Operating Cost and Expense, General [Axis] Component of Other Operating Cost and Expense, Name [Domain] General and Administrative Expense [Member] Professional Fees [Member] Restructuring Charges [Member] Extraordinary Item [Axis] Extraordinary Item, [Domain] Gain on Purchase of Business [Member] Equity Method Investment, Other than Temporary Impairment Payments of Merger Related Costs, Financing Activities Noncash Merger Related Costs General and Administrative [Member] General and Administrative [Member] General and administrative. Equity Method Investment, Ownership Percentage Percentage of equity interest in joint venture Restructuring Charges Pretax Charges Pretax Restructuring charges pretax. Restructuring Charges Tax Charges, tax Restructuring charges tax. Charges Charges. Charges Restructuring Charges [Abstract] Contingencies [Abstract] Commitments and Contingencies Disclosure [Text Block] Contingencies Other Acquisitions Other acquisitions. Other acquisitions Three Point Three Zero Percent Senior Notes due Two Thousand Twenty One [Member] 3.30% Senior Notes due 2021 [Member] Three point three zero percent senior notes due two thousand twenty one. One Point Nine Five Percent Senior Notes due Two Thousand Sixteen [Member] One point nine five percent senior notes due two thousand sixteen. 1.95% Senior Notes due 2016 [Member] Floating Rate Senior Notes due Two Thousand Fourteen [Member] Floating rate senior notes due two thousand fourteen. Floating Rate Senior Notes due 2014 [Member] Line of Credit Facility, Maximum Borrowing Capacity Committed facilities which support commercial paper programs Committed debt facility agreement aggregated Line of Credit Facility, Remaining Borrowing Capacity Unused debt facility Face amount of debt instrument Face amount of debt instrument. face amount of debt instrument Basis Point over Libor Basis Point over LIBOR Basis Point Over LIBOR. Commercial Paper programs maturing December two zero one one [Member] Commercial paper programs maturing December 2011 [Member] Commercial Paper programs maturing December two zero one one. Commercial Paper programs maturing July two zero one six [Member] Commercial paper programs maturing July 2016 [Member] Commercial Paper programs maturing July two zero one six. Westerngeco Electromagnetic Service [Member] Westerngeco Electromagnetic Service. Westerngeco Electromagnetic Service [Member] Proceeds from (Payments for) Other Financing Activities Other