Fair Value Disclosure (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	$ 8.6	$ 38.5	$ 33.9
Operating assets and facilities, net	6,192.1	5,804.7
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset Impairment Charge [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges	8.6	2.0	$ 3.1
Equipment [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Operating assets and facilities, net	$ 32.2	$ 106.6