Shareholders' Equity (Narrative) (Details) - USD ($)				3 Months Ended	12 Months Ended
	Jun. 01, 2015	Dec. 04, 2012	Jun. 08, 2011	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 06, 2012
Class of Stock [Line Items]
Common stock par value (in usd per share)			$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock warrants repurchased					$ 23,000	$ 3,000	$ 30,000
Preferred stock, par value (in usd per share)				$ 0.01	$ 0.01	$ 0.01
Share Price	$ 27.17
Common Stock [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount								$ 100,000,000.0
Treasury stock acquired, average cost per share (in usd per share)					$ 35.90
Stock repurchase program, remaining authorized repurchase amount				$ 26,700,000	$ 26,700,000
Series A [Member]
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percent)	8.50%
Preferred stock, par value (in usd per share)	$ 0.01
Preferred stock, liquidation preference per share (in usd per share)	$ 1,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Conversion of Stock, Shares Issued	36.8046
Series E Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percent)		6.40%
Preferred stock, par value (in usd per share)		$ 0.01
Preferred stock, liquidation preference per share (in usd per share)		$ 25,000
Depository shares, issued		5,060,000
Depository share, par or stated value per share (in usd per share)		$ 25
Warrant [Member]
Class of Stock [Line Items]
Number of securities called by warrants or rights (in shares)			3,282,276
Exercise price of warrants or rights (in usd per share)			$ 18.28
Common stock warrants repurchased			$ 14,400,000
Number of warrants repurchased at auction (in shares)			2,282,276
Number of warrants repurchased (in shares)					1,210
Warrants exercised (in shares)				58,365
Class of Warrant or Right, Outstanding (in shares)				63,344	63,344