Leases - Schedule of Lease Cost Components (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Finance Lease Cost:
Amortization of right of use asset			$ 3.5	$ 1.7
Interest on lease liabilities			1.0	0.5
Operating lease cost			20.8	20.5
Short-term lease cost			1.9	3.1
Variable lease cost			0.9	0.8
Sublease income			(0.1)	0.0
Total lease cost			28.0	26.6
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from finance leases			1.0	0.5
Operating cash flows from operating leases			21.7	20.8
Financing cash flows from finance leases			6.2	2.4
Right of use assets obtained in exchange for new finance lease liabilities			42.3	14.1
Right of use assets obtained in exchange for new operating lease liabilities	[1]		$ 12.4	$ 35.9
Weighted average remaining lease term - finance leases		4 years	4 years	4 years
Weighted average remaining lease term - operating leases		6 years	6 years	6 years
Weighted average discount rate - finance leases		5.30%	6.20%	5.30%
Weighted average discount rate - operating leases		7.00%	6.90%	7.00%
Renewal Option Determined As Reasonably Certain
Cash paid for amounts included in the measurement of lease liabilities
Right of use assets obtained in exchange for new operating lease liabilities		$ 10.2

[1] (a) Several of the Company’s real property lease contracts include options to extend the lease term. During the fourth quarter of 2019 and 2020, the Company reassessed the likelihood of renewal and included $10.2 million for the renewal options in fiscal year ended December 31, 2019 for several of these operating leases in the ROU asset and lease liability because the likelihood of renewal was determined to be reasonably certain. No adjustments were required in 2020 as a result of this reassessment.