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, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net income attributable to controlling interests	$ 37.2	$ 75.4	$ 88.7	$ 156.1
Less: Total income available to participating unvested securities	0.0	0.0	0.0	(0.1)
Total net income attributable to ordinary shares	$ 37.2	$ 75.4	$ 88.7	$ 156.0
Denominator:
Weighted-average shares of common stock outstanding—basic (in shares)	80,001,360	89,970,871	81,832,607	92,996,289
Potential shares of common stock:
Weighted-average shares of common stock outstanding—diluted (in shares)	80,851,538	89,972,300	82,126,530	93,076,064
Earnings per share of common stock attributable to controlling interests:
Basic (in dollars per share)	$ 0.46	$ 0.84	$ 1.08	$ 1.68
Diluted (in dollars per share)	$ 0.46	$ 0.84	$ 1.08	$ 1.68
Restricted stock units
Potential shares of common stock:
Restricted stock units/Employee stock options (in shares)	115,155	1,429	48,915	79,775
Employee stock options
Potential shares of common stock:
Restricted stock units/Employee stock options (in shares)	735,023	0	245,008	0