Asset Impairments - Goodwill Identified, by Segment (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Line Items]
Beginning Balance		$ 2,807	$ 2,807	$ 6,264
Goodwill acquired and adjusted during period			4	62
Impairment	$ 0	(1,295)	(1,295)	(3,509)
Currency translation adjustments and other			(23)	(10)
Ending Balance	1,493		1,493	2,807
Wellbore Technologies [Member]
Goodwill [Line Items]
Beginning Balance		843	843	3,011
Goodwill acquired and adjusted during period			4	9
Impairment			(517)	(2,178)
Currency translation adjustments and other			(22)	1
Ending Balance	308		308	843
Completion & Production Solutions [Member]
Goodwill [Line Items]
Beginning Balance		1,054	1,054	2,041
Goodwill acquired and adjusted during period				40
Impairment			(580)	(1,019)
Currency translation adjustments and other			(1)	(8)
Ending Balance	473		473	1,054
Rig Technologies [Member]
Goodwill [Line Items]
Beginning Balance		$ 910	910	1,212
Goodwill acquired and adjusted during period				13
Impairment			(198)	(312)
Currency translation adjustments and other				(3)
Ending Balance	$ 712		$ 712	$ 910