Earnings Per Share ("EPS") of Common Stock - Reconciliation of Numerator and Denominator (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Net income	$ 27.8	$ 27.8
Income allocated to participating securities	(0.1)	(0.1)
Net income for basic EPS	27.7	27.7
Interest on convertible debt (see Note 1)	0.0	0.7
Net income for diluted EPS	$ 27.7	$ 28.4
Denominator:
Basic weighted average shares (in shares)	80.6	80.2
Effect of:
Awards issued under equity plans (in shares)	0.1	0.0
Convertible debt (See Note 1) (in shares)	0.0	5.6
Diluted weighted average shares (in shares)	80.7	85.8
Basic
Basic earnings per share (in dollars per share)	$ 0.34	$ 0.34
Diluted
Diluted earnings per share (in dollars per share)	$ 0.34	$ 0.33