Goodwill - Schedule of Goodwill (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill beginning balance, gross	$ 2,709
Goodwill ending balance, gross	2,709
Accumulated impairment losses, beginning balance	(2,102)
Accumulated impairment losses, impairment loss	(607)
Accumulated impairment losses, ending balance	(2,709)
Goodwill, beginning balance	607
Impairment loss	$ (607)