Leases - Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finance lease cost:
Amortization of right-of-use assets	$ 3.1	$ 4.2
Interest on lease liabilities	0.6	0.5
Operating lease cost	45.6	53.2
Short-term lease cost	25.5	18.3
Variable lease cost	6.4	5.0
Sublease income	(4.4)	(11.4)
Total lease cost	$ 76.8	$ 69.6
Rental expenses for properties and equipment			$ 48.7

Finance Lease, Cost1 [Abstract]

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- Definition

Amount of interest expense on finance lease liability.

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- Definition

Amount of amortization expense attributable to right-of-use asset from finance lease.

+ References

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- Definition

Amount of lease cost recognized by lessee for lease contract.

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

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- Definition

Amount of short-term lease cost, excluding expense for lease with term of one month or less.

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- Definition

Amount of sublease income excluding finance and operating lease expense.

+ References

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- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

+ References

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