Stock-Based Compensation (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation related to stock plans	$ 1.8	$ 1.6	$ 6.4	$ 6.4
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost			1.2
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	3.4		3.4
Weighted-average period of years costs are expected to be recognied over			1.4
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost			$ 2.2