Leases-The Company as Lessor - Historical Cost and Accumulated Depreciation of Leases Property (Details) (Land and Building, Property Subject to Operating Lease, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Land and Building | Property Subject to Operating Lease
Property Subject to or Available for Operating Lease [Line Items]
Leased property - real estate	$ 1,149.9	$ 1,100.0
Less accumulated depreciation	(118.5)	(99.5)
Property under operating leases - net	$ 1,031.4	$ 1,000.5