Revenues and Long-Lived Assets by Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 1,295	$ 1,283	$ 4,093	$ 4,024
Property and equipment, net	10,379		10,379		$ 10,583
United States
Segment Reporting Information [Line Items]
Revenues	1,247	1,230	3,959	3,857
Property and equipment, net	10,140		10,140		10,294
Australia
Segment Reporting Information [Line Items]
Revenues	8	8	24	25
Property and equipment, net	88		88		88
Brazil
Segment Reporting Information [Line Items]
Revenues	15	7	29	22
Property and equipment, net	63		63		53
Canada
Segment Reporting Information [Line Items]
Revenues	16	15	40	44
Property and equipment, net	73		73		66
Chile
Segment Reporting Information [Line Items]
Revenues		5	9	18
Property and equipment, net					44
Mexico
Segment Reporting Information [Line Items]
Revenues	6	7	21	21
Property and equipment, net	15		15		18
New Zealand
Segment Reporting Information [Line Items]
Revenues	$ 3	$ 11	$ 11	$ 37
Property and equipment, net					$ 20