Share-based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended		9 Months Ended
	May 29, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	4,000,000
Estimated share-based compensation expense		$ 8.7		$ 8.7
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense		1.6	1.7	7.2	7.4
Number of options granted (in shares)				551,740
Weighted-average grant-date fair value per share of options granted (dollars per share)				$ 3.50
Number of options exercised (in shares)				11,881
Stock Options [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense		0.2	0.1	1.5	1.2
Restricted Stock [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense		0.4	0.3	2.7	2.5
Number of shares granted (in shares)				487,290
Weighted average grant date fair value, granted (dollars per share)				$ 6.67
Intrinsic value of shares vested/restrictions lapsed during the period				2.8
Restricted Stock Units Issued to Directors [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense		0.4	0.3	0.9	0.7
Performance Share Awards [Member]
Share-based Compensation Expense [Abstract]
Share-based Compensation Expense		$ 0.6	$ 1.0	$ 2.1	$ 3.0
Number of shares granted (in shares)				512,400
Weighted average grant date fair value, granted (dollars per share)				$ 6.40