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		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
US Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 21	$ 16	$ 43	$ 35
Interest cost	44	35	85	76
Expected return on plan assets	(59)	(44)	(115)	(96)
Amortization of prior service cost	1	3	6	6
Amortization of net loss	31	24	62	44
Total pension cost	38	34	81	65
International
Defined Benefit Plan Disclosure [Line Items]
Service cost	50	29	99	60
Interest cost	75	56	149	128
Expected return on plan assets	(129)	(88)	(257)	(200)
Amortization of prior service cost	31	22	61	52
Amortization of net loss	36	32	74	52
Total pension cost	63	51	126	92
Postretirement medical plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	10	11	21	22
Interest cost	11	15	24	30
Expected return on plan assets	(13)	(10)	(26)	(21)
Amortization of prior service cost	(8)	(1)	(16)	(2)
Amortization of net loss	2	3	7	4
Total pension cost	$ 2	$ 18	$ 10	$ 33