Preferred Stock (Schedule Of Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Apr. 23, 2015
Schedule of Capitalization, Equity [Line Items]
Preferred stock	$ 813	$ 1,255
Stock Repurchased During Period, Value	(325)
Stock Repurchase and Redemption Premium	1,193
Series A Preferred Stock [Member]
Schedule of Capitalization, Equity [Line Items]
Preferred stock	$ 696	$ 1,021
Preferred stock par value (per share)	$ 0.01	$ 0.01
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	40,870,560
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 Repurchase Program, Number of Shares Authorized to be Repurchased			13,000,000
Stock Repurchase Program, Repurchase Price per Share			$ 26.65
Stock Repurchased During Period, Shares	13,000,000
Preferred Stock Repurchase, Aggregate Liquidation Preference	$ 325
Payments for Repurchase of Preferred Stock and Preference Stock	347
Stock Repurchased During Period, Value	325
Stock Repurchase and Redemption Premium	22
Series G Preferred Stock [Member]
Schedule of Capitalization, Equity [Line Items]
Preferred stock	$ 117	$ 234
Preferred stock par value (per share)	$ 0.01	$ 0.01
Liquidation preference (per share)	$ 1,000	$ 1,000
Preferred Stock, Shares Authorized	2,576,601	2,576,601
Preferred Stock, Shares Issued and Outstanding	1,288,301	2,576,601
Preferred Stock, Dividend Rate, Percentage	7.00%	7.00%
Stock Repurchase and Redemption Premium	$ 1,171
Stock Redeemed or Called During Period, Shares	1,288,300
Preferred Stock, Redemption Price Per Share	$ 1,000
Dividends Payable, Amount Per Share	$ 10.50
Preferred Stock Redemption, Aggregate Liquidation Preference	$ 1,288
Preferred Stock, Redemption Amount	1,302
Preferred stock dividends paid for Series G redemption	14
Payments for Repurchase of Redeemable Preferred Stock	$ 117