Goodwill - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 12,968	$ 16,042	$ 24,931
Impairment (see Note 3)		(3,070)	(8,828)
Impact of changes in exchange rates and other	12	(4)	(61)
Goodwill, Ending Balance	12,980	12,968	16,042
Production Systems
Goodwill [Line Items]
Goodwill, Beginning Balance	854
Impact of changes in exchange rates and other	(1)
Goodwill, Ending Balance	853	854
Operating Segments | Reservoir Characterization
Goodwill [Line Items]
Goodwill, Beginning Balance	4,560	4,560	4,703
Impairment (see Note 3)			(97)
Impact of changes in exchange rates and other			(46)
Goodwill, Ending Balance		4,560	4,560
Operating Segments | Drilling
Goodwill [Line Items]
Goodwill, Beginning Balance	5,443	7,092	10,111
Impairment (see Note 3)		(1,659)	(3,025)
Impact of changes in exchange rates and other		10	6
Goodwill, Ending Balance		5,443	7,092
Operating Segments | Production
Goodwill [Line Items]
Goodwill, Beginning Balance	2,704	3,949	4,678
Impairment (see Note 3)		(1,228)	(705)
Impact of changes in exchange rates and other		(17)	(24)
Goodwill, Ending Balance		2,704	3,949
Operating Segments | Cameron
Goodwill [Line Items]
Goodwill, Beginning Balance	261	441	5,439
Impairment (see Note 3)		(183)	(5,001)
Impact of changes in exchange rates and other		3	3
Goodwill, Ending Balance		261	$ 441
Operating Segments | Digital Integration
Goodwill [Line Items]
Goodwill, Beginning Balance	2,041
Impact of changes in exchange rates and other	6
Goodwill, Ending Balance	2,047	2,041
Operating Segments | Reservoir Performance
Goodwill [Line Items]
Goodwill, Beginning Balance	3,806
Impact of changes in exchange rates and other	(4)
Goodwill, Ending Balance	3,802	3,806
Operating Segments | Well Construction
Goodwill [Line Items]
Goodwill, Beginning Balance	6,267
Impact of changes in exchange rates and other	11
Goodwill, Ending Balance	$ 6,278	$ 6,267