Leases - Components of Lease Expense and Other Information (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease expense		$ 35.1	$ 37.4	$ 105.5	$ 109.0
Short-term lease expense		1.4	1.8	4.5	9.0
Variable lease expense	[1]	4.6	3.9	13.6	12.4
Total lease expense		$ 41.1	$ 43.1	123.6	130.4
Supplemental Cash Flow Information
Cash paid for amounts included in the measurement of operating lease liabilities				104.7	107.9
Operating ROU assets obtained in exchange for lease obligations				$ 35.9	$ 56.1

[1] Other lease expense includes variable lease expense and sublease income.