Capital Stock and Net (Loss) Income per Share - Schedule of Computations of Basic and Diluted Net (Loss) Income per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net (loss) income	$ (75.4)	$ (4.0)	$ 78.7
Denominator:
Weighted-average shares outstanding - basic	150,402,321	146,774,471	142,049,112
Effect of dilutive equity instruments			6,707,480
Weighted-average shares outstanding - diluted	150,402,321	146,774,471	148,756,592
Net (loss) income per share - basic	$ (0.50)	$ (0.03)	$ 0.55
Net (loss) income per share - diluted	$ (0.50)	$ (0.03)	$ 0.53