Preferred Stock (Schedule Of Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015	May 16, 2016
Schedule of Capitalization, Equity [Line Items]
Preferred stock	$ 0	$ 696
Preferred Stock, Liquidation Preference Per Share	$ 25
Series A Preferred Stock [Member]
Schedule of Capitalization, Equity [Line Items]
Preferred stock	$ 0	$ 696	$ 696
Preferred stock par value (per share)	$ 0.00	$ 0.01
Preferred Stock, Liquidation Preference Per Share	$ 0	$ 25
Preferred Stock, Shares Authorized	0	40,870,560
Preferred Stock, Shares Issued and Outstanding	0	27,870,560
Preferred Stock, Dividend Rate, Percentage	0.00%	8.50%
Preferred Stock, Dividend Payment Rate, Variable	0	Three month LIBOR + 6.243%
Stock Redeemed or Called During Period, Shares	27,870,560
Preferred Stock, Redemption Price Per Share			$ 25
Dividends Payable, Amount Per Share			$ 0.53
Preferred Stock Redemption, Aggregate Liquidation Preference	$ 697
Preferred Stock, Redemption Amount	712
Preferred stock dividends paid for Series A redemption	$ 15