Income Taxes - U.S. Federal Income Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Computed expected tax benefit (expense)	$ (567)	$ (156)	$ (23)
State and local income taxes, net of federal income taxes	32	(13)	(2)
Foreign taxes, net of foreign tax credit	(8)	1
Change in valuation allowance affecting tax expense	(1)	(1)
Dividends received deduction	6	5	4
Federal tax credits	1	1
Nontaxable consolidation of Expedia	992
Other, net	(4)
Income tax (expense) benefit	451	$ (163)	$ (21)
Gain on consolidation of Expedia	$ 2,005