Debt (Junior Convertible Subordinated Debentures) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	12 Months Ended				12 Months Ended			24 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jul. 15, 2012	Dec. 31, 2012 Junior Subordinated Debt [Member]	Dec. 31, 1997 Junior Subordinated Debt [Member]	Dec. 31, 1997 Convertible Preferred Stock [Member]	Dec. 31, 2005 Convertible Preferred Stock [Member]
Proceeds From Liquidation Of Investment In Unconsolidated Trust					$ 15,500,000
Finance subsidiary ownership percentage						100.00%
Issued shares of convertible preferred securities							10.0
Preferred Stock, Dividend Rate, Percentage							5.25%
Convertible Preferred Securities, Par Value Per Share							$ 50
Convertible Preferred Securities, Dividend Amount Per Share							2.625
Interest rate of junior subordinated debt						5.25%
Incremental Debentures Issued to Unconsolidated Subsidary						15,500,000
Junior Subordinated Debentures Owed to Unconsolidated Subsidiary, Issued						515,500,000
Preferred securities convertible into common stock							0.9865
Convertible Preferred Securities, Shares Repurchased								1.6
Convertible Preferred Securities, Shares Repurchased, Price Per Share								$ 45.27
Convertible Preferred Securities, Shares Repurchased, Amount								71,300,000
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust				436,700,000
Percentage of liquidation preference payable when called							100.00%
Redemption Price As A Percentage Of Face Amount					100.00%
Losses related to extinguishments of debt	$ 0	$ (10,900,000)	$ (4,800,000)		$ 6,000,000