Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Income Tax [Line Items]
Provision for income taxes	$ 16.1		$ (19.3)	$ 62.2	$ (20.9)
Valuation allowance	6.1			6.1		$ 6.6
Reserves released for unrecognized tax benefits		$ (0.7)
Unrecognized tax benefits balance	1.0			1.0		$ 1.7
GILTI [Member]
Income Tax [Line Items]
Provision for income taxes	$ 0.4		$ 2.0	$ 0.7	$ 0.5