Income (Loss) from Continuing Operations Per Unrestricted Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income from Continuing Operations	$ 155.3	$ 53.6
Diluted Income from Continuing Operations Attributed to Unrestricted Shares	$ 154.6	$ 53.1
Weighted-Average Unrestricted Shares Outstanding (shares)	64,815,000.0	51,502,900
Equity-based Compensation Equivalent Shares (shares)	791,000.0	365,300
Weighted-Average Unrestricted Shares and Equivalent Shares Outstanding Assuming Dilution (shares)	65,606,000.0	51,868,200
Basic Income from Continuing Operations Per Unrestricted Share	$ 2.38	$ 1.03
Diluted Income from Continuing Operations Per Unrestricted Share	$ 2.35	$ 1.02
Common Stock [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income from Continuing Operations	$ 154.6	$ 53.1
Participating Awards [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income from Continuing Operations	$ 0.7	$ 0.5