Employee Benefit Plans Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plan | UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans
Service Cost	$ 7.7	$ 9.6	$ 11.0
Interest Cost	67.2	65.0	73.0
Expected Return on Plan Assets	(105.9)	(100.6)	(106.7)
Amortization of Net Actuarial Loss (Gain)	16.3	21.3	18.7
Amortization of Prior Service Cost (Credit)	0.0	0.0	0.1
Curtailment Gain	0.0	0.0	0.0
Net Periodic Benefit Cost	(14.7)	(4.7)	(3.9)
Pension Plan | UNITED KINGDOM
Defined Benefit Plans and Other Postretirement Benefit Plans
Service Cost	0.0	0.0	0.0
Interest Cost	5.0	4.2	4.9
Expected Return on Plan Assets	(10.9)	(9.8)	(9.5)
Amortization of Net Actuarial Loss (Gain)	0.4	1.3	1.1
Amortization of Prior Service Cost (Credit)	0.0	0.0	0.0
Curtailment Gain	0.0	0.0	0.1
Net Periodic Benefit Cost	(5.5)	(4.3)	(3.4)
Other Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Service Cost	0.0	0.0	0.0
Interest Cost	3.0	3.0	4.1
Expected Return on Plan Assets	(0.5)	(0.5)	(0.5)
Amortization of Net Actuarial Loss (Gain)	(1.0)	0.0	0.0
Amortization of Prior Service Cost (Credit)	(0.2)	(0.2)	(0.2)
Curtailment Gain	0.0	0.0	0.0
Net Periodic Benefit Cost	$ 1.3	$ 2.3	$ 3.4