Property and Equipment - Depreciation Expense (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Property, Plant and Equipment [Line Items]
Depreciation and amortization		$ 96	$ 157	$ 198	$ 305
Property, Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciation and amortization	[1]	$ 72	$ 140	$ 148	$ 269

[1] ncluded in depreciation and amortization, corporate expense, and income/(loss) from discontinued operations