Segment Information - Schedule of Segment Reporting Information, by Segment (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Interest expense	$ 130	$ 138	$ 402	$ 419
Operating Segments
Segment Reporting Information [Line Items]
Interest expense	$ 3	$ 7	11	22
Interest income			$ 1	$ 1