Preferred Stock (Schedule Of Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	May. 16, 2016
Schedule of Capitalization, Equity [Line Items]
Preferred stock		$ 696	$ 696
Preferred Stock, Liquidation Preference Per Share		$ 25
Preferred Stock, Redemption Price Per Share				$ 25
Series A Preferred Stock [Member]
Schedule of Capitalization, Equity [Line Items]
Preferred Stock, Notice of Redemption		700,000,000
Preferred stock		$ 696	$ 696
Preferred stock par value (per share)		$ 0.01	$ 0.01
Preferred Stock, Liquidation Preference Per Share		$ 25	$ 25
Preferred Stock, Shares Authorized		40,870,560	40,870,560
Preferred Stock, Shares Issued and Outstanding		27,870,560	27,870,560
Preferred Stock, Dividend Rate, Percentage		8.50%	8.50%
Preferred Stock, Dividend Payment Rate, Variable		Three month LIBOR + 6.243%	Three month LIBOR + 6.243%
Stock Redeemed or Called During Period, Shares	27,870,560