Pension and Other Postretirement Benefit Plans - Net Pension Cost for Schlumberger Pension Plans and US Postretirement Medical Plan (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Postretirement medical plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 7	$ 24	$ 22
Interest cost	11	12	33	35
Expected return on plan assets	(15)	(16)	(47)	(46)
Amortization of prior service cost	(7)	(7)	(21)	(22)
Total pension cost	(3)	(4)	(11)	(11)
US
Defined Benefit Plan Disclosure [Line Items]
Service cost	14	14	44	44
Interest cost	41	44	125	131
Expected return on plan assets	(61)	(60)	(186)	(181)
Amortization of prior service cost	3	3	9	9
Amortization of net loss	12	10	36	29
Total pension cost	9	11	28	32
International
Defined Benefit Plan Disclosure [Line Items]
Service cost	35	24	105	71
Interest cost	77	76	229	230
Expected return on plan assets	(149)	(135)	(442)	(406)
Amortization of prior service cost	3	24	8	73
Amortization of net loss	35	30	105	90
Total pension cost	$ 1	$ 19	$ 5	$ 58