Leases - Lease Cost and Other Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Finance Leases [Abstract]
Amortization of ROU assets	$ 2.7	$ 2.1
Interest on lease liabilities	0.5	0.5
Operating leases	8.1	8.4
Short-term lease cost	0.9	0.9
Variable lease cost	1.6	1.0
Total lease cost	13.8	12.9
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows - finance leases	1.4	0.5
Operating cash flows - operating leases	8.8	8.6
Financing cash flows - finance leases	3.0	2.3
Right-Of-Use Asset Obtained In Exchange For Lease Liability [Abstract]
ROU assets obtained in exchange for new finance lease liabilities	3.4	5.4
ROU assets obtained in exchange for new operating lease liabilities	$ 3.3	$ 3.8
Finance leases
Remaining lease term (in years)	6 years 2 months 12 days	7 years 9 months 18 days
Discount rate	5.00%	5.50%
Operating leases
Remaining lease term (in years)	4 years 9 months 18 days	5 years 1 month 6 days
Discount rate	5.10%	5.60%