Employee Benefits - Net Periodic Pension Expense (Detail) - USD ($) $ in Millions	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2021	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Weighted-Average Assumptions:
Expected Long-Term Rate of Return on Assets			5.25%
Supplemental Plan
Defined Benefit plan Net periodic benefit cost
Service Cost			$ 5.3	$ 4.6	$ 4.1
Interest Cost			3.7	4.8	5.8
Expected Return on Plan Assets			0.0	0.0	0.0
Amortization:
Net Actuarial Loss			8.2	7.0	5.6
Prior Service (Credit) Cost			0.1	0.2	0.2
Net Periodic Pension Expense			17.3	16.6	15.7
Settlement Expense			0.0	0.0	0.0
Total Pension Expense			$ 17.3	$ 16.6	$ 15.7
Weighted-Average Assumptions:
Discount Rates			2.45%	3.37%	4.47%
Rate of Increase in Compensation Level			4.97%	4.97%	4.39%
U.S. Plan | Pension Plans, Defined Benefit
Defined Benefit plan Net periodic benefit cost
Service Cost			$ 52.3	$ 47.4	$ 41.6
Interest Cost			40.4	43.3	47.2
Expected Return on Plan Assets			(79.0)	(76.8)	(86.9)
Amortization:
Net Actuarial Loss			32.4	35.0	17.2
Prior Service (Credit) Cost			(0.4)	(0.4)	(0.4)
Net Periodic Pension Expense			45.7	48.5	18.7
Settlement Expense			27.9	0.0	0.0
Total Pension Expense			$ 73.6	$ 48.5	$ 18.7
Weighted-Average Assumptions:
Discount Rates				3.37%	4.47%
Rate of Increase in Compensation Level			4.97%	4.97%	4.39%
Expected Long-Term Rate of Return on Assets				5.25%	6.00%
U.S. Plan | Pension Plans, Defined Benefit | Lower Limit
Weighted-Average Assumptions:
Discount Rates			2.75%	2.75%
Expected Long-Term Rate of Return on Assets	5.25%	5.00%	5.25%	5.25%
U.S. Plan | Pension Plans, Defined Benefit | Upper Limit
Weighted-Average Assumptions:
Discount Rates	3.05%	3.06%	3.03%
Expected Long-Term Rate of Return on Assets			5.00%
Non U.S. Plans | Pension Plans, Defined Benefit
Defined Benefit plan Net periodic benefit cost
Service Cost			$ 2.2	$ 1.9	$ 2.0
Interest Cost			2.2	2.9	3.9
Expected Return on Plan Assets			(3.2)	(3.1)	(4.4)
Amortization:
Net Actuarial Loss			1.0	0.8	0.6
Prior Service (Credit) Cost			0.2	0.4	0.3
Net Periodic Pension Expense			2.4	2.9	2.4
Settlement Expense			0.4	0.8	0.0
Total Pension Expense			$ 2.8	$ 3.7	$ 2.4
Weighted-Average Assumptions:
Discount Rates			0.93%	1.40%	2.16%
Rate of Increase in Compensation Level			1.50%	1.50%	1.75%
Expected Long-Term Rate of Return on Assets			1.28%	1.72%	2.39%