Pension and Other Postretirement Benefits - Net Pension Cost for Schlumberger Pension Plans and US Postretirement Medical Plan (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
US Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during period	$ 21	$ 17	$ 41	$ 34
Interest cost on benefit obligation	38	38	75	76
Expected return on plan assets	(51)	(47)	(103)	(93)
Amortization of prior service cost	3	3	6	6
Amortization of net loss	31	23	63	46
Total pension cost	42	34	82	69
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during period	34	21	67	42
Interest cost on benefit obligation	63	58	124	116
Expected return on plan assets	(100)	(80)	(200)	(160)
Amortization of prior service cost	29	30	59	60
Amortization of net loss	37	15	74	30
Total pension cost	63	44	124	88
Postretirement medical plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during period	12	7	24	14
Interest cost on benefit obligation	15	15	30	30
Expected return on plan assets	(9)	(7)	(18)	(14)
Amortization of prior service cost	(1)	(2)	(2)	(4)
Amortization of net loss	8	5	15	10
Total pension cost	$ 25	$ 18	$ 49	$ 36