Lease Disclosures - Future Minimum Lease Rents (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2017
Future Minimum Lease Rents Due [Abstract]
Asset cost of leased property		$ 89.0		$ 89.0
Carrying amount on leased property		58.8		$ 60.0
Contingent rent expense on leases	$ 2.6	2.7
Minimum rent expense on leases	$ 73.0	$ 80.8
Direct Financing Lease, 2019			$ 16.2
Direct Financing Lease, 2020			14.8
Direct Financing Lease, 2021			11.7
Direct Financing Lease, 2022			8.2
Direct Financing Lease, 2023			3.5
Thereafter			2.9
Total minimum rents receivable			57.3
Operating Lease, 2019			105.9
Operating Lease, 2020			106.3
Operating Lease, 2021			100.2
Operating Lease, 2022			96.2
Operating Lease, 2023			91.8
Thereafter			271.8
Total minimum rents receivable			$ 772.2