Revenues and Long-Lived Assets by Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues	$ 844	$ 198	$ 1,892	$ 1,353
Property and equipment, net	10,124		10,124		$ 9,416
United States
Segment Reporting Information [Line Items]
Revenues	835	196	1,878	1,335
Property and equipment, net	10,047		10,047		9,331
Brazil
Segment Reporting Information [Line Items]
Revenues	3	1	5	6
Property and equipment, net	31		31		34
Canada
Segment Reporting Information [Line Items]
Revenues	6	$ 1	9	$ 12
Property and equipment, net	$ 46		$ 46		$ 51