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, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
US Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 22	$ 19	$ 65	$ 54
Interest cost	42	47	127	123
Expected return on plan assets	(57)	(60)	(172)	(156)
Amortization of prior service cost	3	3	9	9
Amortization of net loss (gain)	30	17	92	61
Total pension cost	40	26	121	91
International
Defined Benefit Plan Disclosure [Line Items]
Service cost	30	38	128	98
Interest cost	75	90	224	218
Expected return on plan assets	(125)	(143)	(381)	(343)
Amortization of prior service cost	30	38	91	90
Amortization of net loss (gain)	54	18	128	70
Total pension cost	64	41	190	133
Postretirement medical plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	11	10	32	32
Interest cost	12	15	36	45
Expected return on plan assets	(13)	(12)	(39)	(33)
Amortization of prior service cost	(8)	(1)	(24)	(3)
Amortization of net loss (gain)	3	(3)	10	1
Total pension cost	$ 5	$ 9	$ 15	$ 42