Revenues and Long-Lived Assets by Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 1,459	$ 1,439	$ 2,798	$ 2,741
Property and equipment, net	10,452		10,452		$ 10,583
United States
Segment Reporting Information [Line Items]
Revenues	1,415	1,384	2,711	2,627
Property and equipment, net	10,211		10,211		10,294
Australia
Segment Reporting Information [Line Items]
Revenues	8	8	16	17
Property and equipment, net	87		87		88
Brazil
Segment Reporting Information [Line Items]
Revenues	7	8	14	15
Property and equipment, net	64		64		53
Canada
Segment Reporting Information [Line Items]
Revenues	14	15	24	29
Property and equipment, net	74		74		66
Chile
Segment Reporting Information [Line Items]
Revenues	4	6	9	13
Property and equipment, net					44
Mexico
Segment Reporting Information [Line Items]
Revenues	8	7	15	14
Property and equipment, net	16		16		18
New Zealand
Segment Reporting Information [Line Items]
Revenues	$ 3	$ 11	$ 9	$ 26
Property and equipment, net					$ 20