Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Income (Loss) Attributable to Parent [Abstract]
Income from continuing operations	$ 925.2	$ 387.0	$ 325.7
Less: dividends declared	134.6	112.7	112.7
Undistributed earnings	$ 790.6	$ 274.3	$ 213.0
Percent allocated to common stockholders	99.80%	99.70%	99.70%
Undistributed earnings available to common shareholders	$ 788.8	$ 273.5	$ 212.4
Add: dividends declared to common shares, restricted share units and vested and deferred restricted and performance shares	134.2	112.4	112.2
Income from continuing operations attributable to common stockholders	$ 923.0	$ 385.9	$ 324.6
Shares:
Basic weighted-average shares outstanding (in shares)	51.8	52.5	54.5
Effect of dilutive securities:
Performance awards (in shares)	0.2	0.2	0.3
Stock options (in shares)	0.5	0.5	0.2
Diluted weighted-average shares outstanding (in shares)	52.5	53.2	55.0
Per share income from continuing operations attributable to common shares:
Basic (in dollars per share)	$ 17.82	$ 7.35	$ 5.95
Diluted (in dollars per share)	$ 17.58	$ 7.26	$ 5.90
Basic weighted-average shares outstanding (in shares)	51.8	52.5	54.5
Basic weighted-average shares outstanding and unvested restricted shares expected to vest (in shares)	51.9	52.6	54.7
Percent allocated to common stockholders	99.80%	99.70%	99.70%
Anti-dilutive stock options excluded from EPS calculation
(Loss) income from discontinued operations attributable to common stockholders for basic and dilutive earnings per share	$ (1.2)	$ 34.6	$ (5.6)
Net income attributable to common stockholders for basic and diluted earnings per share	$ 921.8	$ 420.5	$ 319.0
Antidilutive stock options excluded from earnings per share calculation (in shares)	0.2	0.1	0.3