Income Taxes (Details 3) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets
Deferred and refundable income taxes	$ 75	$ 94
Deferred tax liabilities
Deferred income taxes and other liabilities	(812)	(668)
Deferred income taxes, net	$ (737)	$ (574)