Leases - Maturities on leases (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Operating Leases
2019	$ 4.0
2020	8.2
2021	5.8
2022	3.0
2023	2.6
2024	2.9
Thereafter	4.2
Total undiscounted lease payments	30.7
Imputed interest	(3.0)
Debt financing costs	0.0
Total lease liabilities	27.7
Finance Leases
2019	12.0
2020	22.1
2021	21.8
2022	725.4
2023	0.0
2024	0.0
Thereafter	0.0
Total undiscounted lease payments	781.3
Imputed interest	(63.3)
Debt financing costs	(6.7)
Finance lease liabilities	$ 711.3
Operating Leases
2019		$ 10.4
2020		3.8
2021		3.4
2022		2.2
2023		1.5
Thereafter		4.1
Operating Leases		25.4
Capital and Facility Lease Obligations
2019		26.4
2020		28.4
2021		27.9
2022		7.0
2023		0.0
Thereafter		0.0
Capital and Facility Lease Obligations		$ 89.7