Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Income from continuing operations, net of income attributable to non-controlling interest	$ 60.9	$ 28.8
Denominator:
Denominator for basic earnings per common share-weighted average shares (in shares)	53.4	54.7
Effect of dilutive securities:
Employee stock-based compensation (in shares)	0.6	1.0
Denominator for diluted earnings per common share-adjusted weighted average shares	54.0	55.7
Basic earnings per share for continuing operations (in dollars per share)	$ 1.14	$ 0.53
Diluted earnings per share for continuing operations (in dollars per share)	$ 1.13	$ 0.52
Shares excluded from diluted earnings per common share computation as anti-dilutive (in shares)	0.2	1.2