Revenues and Long-Lived Assets by Geographical Area (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 1,431	$ 1,399	$ 2,740	$ 2,624
Property and equipment, net	10,749		10,749		10,995
United States
Segment Reporting Information [Line Items]
Revenues	1,358	1,332	2,601	2,492
Property and equipment, net	10,236		10,236		10,498
Australia
Segment Reporting Information [Line Items]
Revenues	10	10	19	20
Property and equipment, net	112		112		106
Brazil
Segment Reporting Information [Line Items]
Revenues	12	8	19	15
Property and equipment, net	87		87		76
Canada
Segment Reporting Information [Line Items]
Revenues	24	26	44	47
Property and equipment, net	86		86		89
Chile
Segment Reporting Information [Line Items]
Revenues	8	8	16	17
Property and equipment, net	50		50		54
Mexico
Segment Reporting Information [Line Items]
Revenues	7	5	14	11
Property and equipment, net	31		31		32
New Zealand
Segment Reporting Information [Line Items]
Revenues	12	10	27	22
Property and equipment, net	$ 147		$ 147		$ 140