Summary of Accounting Policies - Reconciliation of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Income (Loss) Attributable to Schlumberger
Basic	$ (10,518)	$ (10,137)	$ 2,138
Diluted	$ (10,518)	$ (10,137)	$ 2,138
Average Shares Outstanding
Basic	1,390	1,385	1,385
Unvested restricted stock			8
Diluted	1,390	1,385	1,393
Earnings (Loss) per Share
Basic	$ (7.57)	$ (7.32)	$ 1.54
Diluted	$ (7.57)	$ (7.32)	$ 1.53