Revenues and Long-Lived Assets by Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 198	$ 1,262	$ 1,353	$ 4,135
Property and equipment, net	9,487		9,487		$ 9,671
United States
Segment Reporting Information [Line Items]
Revenues	196	1,239	1,335	4,070
Property and equipment, net	9,405		9,405		9,570
Brazil
Segment Reporting Information [Line Items]
Revenues	1	6	6	17
Property and equipment, net	32		32		45
Canada
Segment Reporting Information [Line Items]
Revenues	1	$ 17	12	$ 48
Property and equipment, net	$ 50		$ 50		$ 56