Earnings Per Share - Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net Income (Loss) Attributable to Parent	$ 196.4	$ 112.9	$ 360.0	$ 138.2
Denominator:
Weighted average shares outstanding	37,799,000	38,459,000	38,093,000	38,289,000
Dilutive effect of stock-based awards	725,000	271,000	779,000	397,000
Weighted average shares outstanding adjusted for dilutive securities	38,524,000	38,730,000	38,872,000	38,686,000
Earnings Per Share Basic Diluted [Abstract]
Basic	$ 5.20	$ 2.94	$ 9.45	$ 3.61
Diluted	$ 5.10	$ 2.91	$ 9.26	$ 3.57