CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 494	$ 441	$ 923	$ 971
Currency translation adjustments
Unrealized net change arising during the period	(37)	(121)	39	(81)
Marketable securities
Unrealized loss arising during the period		(40)		(21)
Cash flow hedges
Net gain (loss) on cash flow hedges	1	(15)	(4)	(10)
Reclassification to net income of net realized (gain) loss	1	(1)	4	(5)
Pension and other postretirement benefit plans
Amortization to net income of net actuarial loss	23	37	47	94
Amortization to net income of net prior service credit	(3)	(1)	(6)	(3)
Income taxes on pension and other postretirement benefit plans	(2)	(5)	(2)	(5)
Comprehensive income	477	295	1,001	940
Comprehensive income attributable to noncontrolling interests	2	11	10	16
Comprehensive income attributable to Schlumberger	$ 475	$ 284	$ 991	$ 924