Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
U.S. federal income taxes (including foreign withholding taxes):
Current federal income taxes	$ 105.4	$ (52.6)	$ 92.2
Deferred federal income taxes	13.2	(12.0)	9.5
Total federal income taxes	118.6	(64.6)	101.7
State and local income taxes:
Current state and local income taxes	27.4	(3.7)	10.7
Deferred state and local income taxes	(0.9)	0.5	8.7
Total state and local income taxes	26.5	(3.2)	19.4
Foreign income taxes:
Current foreign income taxes	127.2	110.7	92.2
Deferred foreign income taxes	(20.5)	(34.9)	(8.5)
Total foreign income taxes	106.7	75.8	83.7
Provision for income taxes	$ 251.8	$ 8.0	$ 204.8