Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net income to common shareholders	$ 44.1	$ 126.4	$ 85.6	$ 141.6
Basic weighted average shares outstanding (in shares)	221.0	232.5	222.8	233.2
Diluted weighted average shares outstanding (in shares)	221.4	233.5	223.3	234.1
Net income per common share:
Basic net income per share (in dollars per share)	$ 0.20	$ 0.54	$ 0.38	$ 0.61
Diluted net income per share (in dollars per share)	$ 0.20	$ 0.54	$ 0.38	$ 0.60
Antidilutive securities excluded from computation of earnings per share (in shares)	1.3	0.6	1.2	1.1