Leases - Supplemental Cash Flow and Other Information Related to Leases (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Lease cost
Amortization of right-of-use assets	$ 15.5
Interest on lease liabilities	3.1
Operating lease cost	6.0
Short-term lease cost	6.2
Total lease cost	30.8
Other information
Operating cash flows from finance leases	3.1
Operating cash flows from operating leases	5.0
Financing cash flows from finance leases	35.7
Right-of-use assets obtained in exchange for new finance lease liabilities	19.2
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 7.0
Weighted average remaining lease terms
Weighted-average remaining lease term (in years) - finance leases	2 years 7 days
Weighted-average remaining lease term (in years) - operating leases	15 years 6 months 3 days
Discount rates
Weighted-average discount rate - finance leases	5.00%
Weighted-average discount rate - operating leases	4.80%