Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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The cash outflow to reacquire common stock during the period.

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Share Based Compensation (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			288,000
Share-based compensation expense	$ 3.9	$ 4.1	$ 9.8	$ 13.7
Tax benefit from share-based compensation expense	$ 1.0	$ 1.0	2.5	3.4
Payments for Repurchase of Common Stock			$ 0.0	$ 129.0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			34,950
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			54,270
Phantom Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			20,361