Retirement and Deferred Compensation Plans - Reconciliation of Changes in Benefit Obligations and the Statement of Funded Status of Plan (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 29, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in Plan Assets
Settlements	$ (3.2)
Pension Plan
Change in Benefit Obligation
Service cost		$ 21.0	$ 15.1	$ 10.9
Interest cost		9.4	12.7	11.6
Pension Plan | United States Plans
Change in Benefit Obligation
Benefit obligation, beginning of year		52.8	48.9
Interest cost		0.8	1.8
Settlements		(22.3)
Actuarial (gain) loss		(0.4)	6.3
Benefits paid		(2.4)	(4.2)
Benefit obligation, end of year		28.5	52.8	48.9
Change in Plan Assets
Fair value of plan assets, beginning of year		38.8	36.1
Actual return on plan assets		0.1	4.4
Settlements		(22.3)
Company contributions		(14.2)	2.5
Benefits paid		(2.4)	(4.2)
Fair value of plan assets, end of year			38.8	36.1
Funded Status at End of Year
Funded status, end of year		(28.5)	(14.0)
Amounts Recognized
Noncurrent assets			15.0
Current liabilities		(2.4)	(2.5)
Noncurrent liabilities		(26.1)	(26.5)
Net amount recognized		(28.5)	(14.0)
Pension Plan | Non-United States Plans
Change in Benefit Obligation
Benefit obligation, beginning of year		794.8	450.0
Service cost		21.0	15.1
Interest cost		8.6	10.9
Acquisitions			201.2
Settlements		(42.2)	(40.9)
Transfers		27.0	52.7
Actuarial (gain) loss		90.9	100.1
Plan participant contributions		11.6	9.0
Benefits paid		(13.2)	(11.3)
Currency exchange rate changes		67.1	8.0
Benefit obligation, end of year		965.6	794.8	450.0
Change in Plan Assets
Fair value of plan assets, beginning of year		655.4	354.1
Actual return on plan assets		49.7	69.5
Acquisitions			196.8
Settlements		(42.2)	(40.9)
Transfers		26.2	51.6
Plan participant contributions		11.6	9.0
Company contributions		16.1	15.4
Benefits paid		(13.2)	(11.3)
Currency exchange rate changes		50.0	11.2
Fair value of plan assets, end of year		753.6	655.4	354.1
Funded Status at End of Year
Funded status, end of year		(211.9)	(139.4)
Amounts Recognized
Noncurrent assets		32.1	41.4
Current liabilities		(1.2)	(0.7)
Noncurrent liabilities		(242.8)	(180.1)
Net amount recognized		(211.9)	(139.4)
Retiree health care plan
Change in Benefit Obligation
Benefit obligation, beginning of year		14.1	13.7
Interest cost		0.4	0.5	0.5
Actuarial (gain) loss		1.0	0.8
Benefits paid		(0.9)	(0.9)
Benefit obligation, end of year		14.6	14.1	$ 13.7
Funded Status at End of Year
Funded status, end of year		(14.6)	(14.1)
Amounts Recognized
Current liabilities		(1.1)	(1.1)
Noncurrent liabilities		(13.5)	(13.0)
Net amount recognized		$ (14.6)	$ (14.1)