Income Tax (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Income from before taxes subject to US and Non-US Income Taxes
United States	$ 591	$ 365
Outside United States	1,130	873
Income (Loss) from Continuing Operations before Income Taxes and Minority Interest, Total	$ 1,721	$ 1,238

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 foreign country.

No definition available.

Name:	slb_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeignCountry
Namespace Prefix:	slb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration