Shareholders' Equity - Treasury Stock (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended		41 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	May. 02, 2012
Equity [Abstract]
Number of shares authorized to be repurchased (in shares)				5,000,000
Number shares repurchased (in shares)	382,448		3,000,000
Payments for repurchase of common stock	$ 1.7	$ 2.5	$ 13.3
Remaining number of shares authorized to be repurchased (in shares)	2,000,000		2,000,000
Average price per share of treasury stock acquired and held (in dollars per share)			$ 12.74
Movement in Treasury Stock [Roll Forward]
Beginning balance (in shares)	627,796
Purchases (in shares)	382,448		3,000,000
Exercise of stock options (in shares)	(12,656)
Restricted stock grants (in shares)	(690,662)
Forfeitures and other (in shares)	931,058
Ending balance (in shares)	1,237,984		1,237,984