Revenues and Long-Lived Assets by Geographical Area (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 1,294	$ 1,211	$ 4,034	$ 3,835
Property and equipment, net	10,629		10,629		10,995
United States
Segment Reporting Information [Line Items]
Revenues	1,225	1,148	3,826	3,640
Property and equipment, net	10,149		10,149		10,498
Australia
Segment Reporting Information [Line Items]
Revenues	10	10	29	30
Property and equipment, net	109		109		106
Brazil
Segment Reporting Information [Line Items]
Revenues	9	7	29	22
Property and equipment, net	84		84		76
Canada
Segment Reporting Information [Line Items]
Revenues	22	22	65	69
Property and equipment, net	82		82		89
Chile
Segment Reporting Information [Line Items]
Revenues	7	7	23	24
Property and equipment, net	46		46		54
Mexico
Segment Reporting Information [Line Items]
Revenues	7	6	21	17
Property and equipment, net	30		30		32
New Zealand
Segment Reporting Information [Line Items]
Revenues	14	11	41	33
Property and equipment, net	$ 129		$ 129		$ 140