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Stock-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Stock-Based Compensation (Details) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit	$ 0.4	$ 0.4	$ 0.9	$ 0.9
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	1.6	1.3	3.4	3.4
Share-based Payment Arrangement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	1.7	1.3	3.7	3.4
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	0.1	0.0	$ 0.3	0.0
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture			164,794
Total Shareholder Return [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	0.8	0.6	$ 2.3	2.1
Performance Units Related to Earnings Per Share [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 0.8	$ 0.7	$ 1.1	$ 1.3