CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statement of Comprehensive Income [Abstract]
Net income	$ 1,310	$ 943
Currency translation adjustments
Unrealized net change arising during the period	111	129
Derivatives
Net derivatives gain (loss) on hedge transactions	155	192
Reclassification to net income of net realized (gain) loss	(110)	227
Actuarial loss
Actuarial loss arising during the period	(28)	(11)
Amortization to net income of net actuarial loss	43	33
Prior service cost
Prior service credit arising during the period		1
Amortization to net income of net prior service cost	31	30
Income taxes on pension and other postretirement benefit plans	(10)	(22)
Comprehensive income	1,502	1,068
Comprehensive income (loss) attributable to noncontrolling interests	9	(1)
Comprehensive income attributable to Schlumberger	$ 1,493	$ 1,069