Commitments and Contingencies Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Capital Leased Assets, Gross	$ 71.4	$ 35.9
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation	9.0	3.3
Capital Leases, Lessor Balance Sheet, Net Investment in Direct Financing Leases, Current	2.1
Operating Leases, Rent Expense	$ 64.1	$ 36.6	$ 30.6