Pension and Other Postretirement Benefit Plans - Net Pension Cost (Credit) for Schlumberger Pension Plans and US Postretirement Medical Plan (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Curtailment gain			$ 69
Postretirement medical plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5	$ 8	23	$ 23
Interest cost	7	12	27	36
Expected return on plan assets	(19)	(16)	(52)	(49)
Amortization of prior service cost	(4)	(7)	(19)	(21)
Total pension cost (credit)	(11)	(3)	(90)	(11)
Curtailment gain			(69)
US
Defined Benefit Plan Disclosure [Line Items]
Service cost	10	14	41	41
Interest cost	36	45	111	136
Expected return on plan assets	(58)	(58)	(175)	(173)
Amortization of prior service cost	2	3	6	7
Amortization of net loss	9	7	31	23
Total pension cost (credit)	(1)	11	14	34
International
Defined Benefit Plan Disclosure [Line Items]
Service cost	31	32	105	96
Interest cost	76	82	226	248
Expected return on plan assets	(148)	(148)	(443)	(446)
Amortization of prior service cost		2		6
Amortization of net loss	39	16	119	47
Total pension cost (credit)	$ (2)	$ (16)	$ 7	$ (49)