Pension and Other Benefit Plans - Net Pension Cost for Schlumberger Pension Plans and US Postretirement Medical Plan (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
US Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	$ 72	$ 80	$ 68
Interest cost on projected benefit obligation and on accumulated postretirement benefit obligation	164	150	152
Expected return on plan assets	(208)	(200)	(185)
Amortization of net loss	82	122	95
Amortization of prior service cost	12	12	12
Total pension cost	122	164	142
International
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	126	127	86
Interest cost on projected benefit obligation and on accumulated postretirement benefit obligation	288	253	241
Expected return on plan assets	(450)	(384)	(328)
Amortization of net loss	94	155	76
Amortization of prior service cost	120	117	120
Total pension cost	178	268	195
Postretirement medical plan
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	43	48	29
Interest cost on projected benefit obligation and on accumulated postretirement benefit obligation	60	56	58
Expected return on plan assets	(45)	(37)	(30)
Amortization of net loss	1	23	16
Amortization of prior service cost	(4)	(4)	(7)
Total pension cost	$ 55	$ 86	$ 66