Equity Level 4 Preferred Stock & SE Warrants (Details) (USD $)	0 Months Ended
	Mar. 23, 2010	Mar. 30, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 17, 2008	Mar. 31, 2013
Class of Stock [Line Items]
Depository shares, issued	23,000,000
Interest in mandatory convertible preferred stock series F represented by each depositary share	1/40th
Sale of depository shares price per share	$ 25
Net proceeds from issuance of depository shares	$ 556,000,000
Exercise price of warrant			$ 9.388	$ 9.504	$ 9.599
Warrants Issued to Allianz [Member]
Class of Stock [Line Items]
Exercise price of warrant		$ 25.23
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		69,351,806
Reclassification of Warrants from Equity to Other Liabilities		$ 300
Note Warrant [Member] | Warrants For Series B And C Before Anti Dilution Provision Trigger [Member]
Class of Stock [Line Items]
Exercise price of warrant						$ 25.32
Class of Warrant or Right, Number of Securities Called by Warrants or Rights						69,115,324
Series F Preferred Stock [Member]
Class of Stock [Line Items]
Cumulative dividend on mandatory convertible preferred stock	7.25%
Preferred stock, liquidation preference per share	$ 1,000
Convertible preferred stock shares, Series F, reserved for future issuance							21,200,000