Pension and Other Employee Benefits - Other Recognized Change in Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Pension liability adjustment, net of tax	$ 3.3	$ (2.6)	$ (1.4)
Incurred net actuarial (loss) gain	1.3	(2.6)	(1.4)
Amortization of prior service credit		(0.1)	(0.1)
Amortization of net actuarial (loss) gain	0.6	0.5	0.2
Settlement recognition of net actuarial (loss)	0.7
Total recognized in accumulated other comprehensive (loss) income (net of ($0.6 million), $0.5 million and $0.8 million) of tax (loss)/benefit, respectively)	$ 2.6	$ (2.2)	$ (1.3)