Postretirement Benefit Plans - Changes in Fair Value of Plan Assets of Pension and Other Employee-Related Defined Benefit Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Change in plan assets
Plan assets – January 1	$ 0.5	$ 321.8
Actual return on plan assets	0.0	20.0
Employer contributions	10.5	18.0
Benefits and expenses paid	(10.3)	(30.8)
Settlement	(0.2)	(328.5)
Plan assets – December 31	0.5	0.5
Funded status at end of year	(213.8)	(242.3)
Pension Plan [Member]
Change in plan assets
Plan assets – January 1	0.5
Plan assets – December 31	0.5	0.5
Funded status at end of year	(107.4)	(124.0)
Pension Plan [Member] | United States
Change in plan assets
Plan assets – January 1	0.0	319.9
Actual return on plan assets	0.0	20.0
Employer contributions	0.9	9.3
Benefits and expenses paid	(0.9)	(21.3)
Settlement	0.0	(327.9)
Plan assets – December 31	0.0	0.0
Funded status at end of year	(14.8)	(15.5)
Pension Plan [Member] | International Plan [Member]
Change in plan assets
Plan assets – January 1	0.5	0.6
Actual return on plan assets	0.0	0.0
Employer contributions	3.4	4.1
Benefits and expenses paid	(3.2)	(3.6)
Settlement	(0.2)	(0.6)
Plan assets – December 31	0.5	0.5
Funded status at end of year	(92.6)	(108.5)
Other Postretirement Benefits Plan [Member]
Change in plan assets
Plan assets – January 1	0.0	1.3
Actual return on plan assets	0.0	0.0
Employer contributions	6.2	4.6
Benefits and expenses paid	(6.2)	(5.9)
Settlement	0.0	0.0
Plan assets – December 31	0.0	0.0
Funded status at end of year	$ (106.4)	$ (118.3)