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
	Mar. 31, 2015	Mar. 31, 2014
US Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during period	$ 22	$ 19
Interest cost on projected benefit obligation and on accumulated postretirement benefit obligation	41	41
Expected return on plan assets	(56)	(52)
Amortization of prior service cost	5	3
Amortization of net loss	31	20
Total pension cost	43	31
International
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during period	49	31
Interest cost on projected benefit obligation and on accumulated postretirement benefit obligation	74	72
Expected return on plan assets	(128)	(113)
Amortization of prior service cost	30	30
Amortization of net loss	38	20
Total pension cost	63	40
Postretirement medical plan
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during period	11	11
Interest cost on projected benefit obligation and on accumulated postretirement benefit obligation	13	15
Expected return on plan assets	(13)	(11)
Amortization of prior service cost	(8)	(1)
Amortization of net loss	5	1
Total pension cost	$ 8	$ 15