Income Taxes (Schedule of Reconciliation of the Total Amount of Unrecognized Tax Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit, beginning of year	$ 16		$ 1
Gross increases - assumed liability of acquired entity		$ 26
Reductions - tax positions in prior period		(8)
Lapse of statute of limitations	(1)	(1)
Settlements		(1)	$ (1)
Unrecognized tax benefit, end of year	$ 15	$ 16