Earnings per Common Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share, Basic and Diluted [Line Items]
Net income	$ 67.0	$ 64.1	$ 123.3	$ 30.7
Weighted average common shares outstanding for basic earnings per share computation (in shares)	103,820,649	109,106,891	103,779,386	101,025,926
Dilutive effects of stock-based compensation (in shares)	2,242	24,827	42,539	50,405
Weighted average common shares outstanding for diluted earnings per common share computation (in shares)	103,822,891	109,131,718	103,821,925	101,076,331
Basic earnings per common share (in dollars per share)	$ 0.65	$ 0.59	$ 1.19	$ 0.30
Diluted earnings per common share (in dollars per share)	$ 0.65	$ 0.59	$ 1.19	$ 0.30
Restricted Stock
Earnings Per Share, Basic and Diluted [Line Items]
Anti-dilutive unvested time restricted stock (in shares)	222,417	218,033	129,449	61,058
Unvested restricted stock
Earnings Per Share, Basic and Diluted [Line Items]
Anti-dilutive unvested time restricted stock (in shares)			974,875	500,573