Earnings Per Share - Calculation of Pro Forma Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator:
Net income attributable to controlling interests	$ 19.6	$ 17.8	$ 43.0	$ 70.2
Denominator:
Weighted-average shares of common stock outstanding—basic (in shares)	41,508,143	41,431,729	41,479,116	42,266,420
Potential shares of common stock:
Weighted-average shares of common stock outstanding—diluted (in shares)	42,589,717	42,353,442	42,648,805	43,390,502
Earnings per share of common stock attributable to controlling interests:
Basic (in dollars per share)	$ 0.47	$ 0.43	$ 1.04	$ 1.66
Diluted (in dollars per share)	$ 0.46	$ 0.42	$ 1.01	$ 1.62
Restricted stock units
Potential shares of common stock:
Restricted stock units/Employee stock options (in shares)	7,471	14,294	5,568	10,542
Employee stock options
Potential shares of common stock:
Restricted stock units/Employee stock options (in shares)	1,074,103	907,419	1,164,121	1,113,540