Leases - Future Minimum Lease Rents (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Future Minimum Lease Rents Due [Abstract]
Asset Cost of Leased Property	$ 89.0	$ 89.0
Carrying Amount on Leased Property	61.3	62.7
Contingent Rent Expense on Leases	3.0	3.3	$ 2.8
Minimum Rent Expense on Leases	76.5	$ 80.9	$ 75.9
Direct Financing Lease, 2017	17.6
Direct Financing Lease, 2018	17.2
Direct Financing Lease, 2019	16.1
Direct Financing Lease, 2020	14.8
Direct Financing Lease, 2021	11.7
Thereafter	14.7
Total minimum rents receivable	92.1
Operating Lease, 2017	101.4
Operating Lease, 2018	100.9
Operating Lease, 2019	99.2
Operating Lease, 2020	99.3
Operating Lease, 2021	93.0
Thereafter	406.0
Total minimum rents receivable	$ 899.8