Pension and Other Postretirement Benefit Plans - Net Pension Cost for Schlumberger Pension Plans and US Postretirement Medical Plan (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
US Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during period	$ 19	$ 19	$ 54	$ 60
Interest cost on projected benefit obligation	47	38	123	113
Expected return on plan assets	(60)	(47)	(156)	(150)
Amortization of prior service cost	3	3	9	9
Amortization of net loss	17	28	61	91
Total pension cost	26	41	91	123
International
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during period	38	28	98	95
Interest cost on projected benefit obligation	90	65	218	189
Expected return on plan assets	(143)	(88)	(343)	(288)
Amortization of prior service cost	38	29	90	88
Amortization of net loss	18	43	70	117
Total pension cost	41	77	133	201
Postretirement medical plan
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during period	10	12	32	36
Interest cost on projected benefit obligation	15	14	45	42
Expected return on plan assets	(12)	(9)	(33)	(28)
Amortization of prior service cost	(1)	(1)	(3)	(3)
Amortization of net loss	(3)	2	1	17
Total pension cost	$ 9	$ 18	$ 42	$ 64