Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Type of Entity	one
Variable Interest, Held by Entity [Member]
Carrying amounts of assets and liabilities of the VIE
Operating assets, net of accumulated depreciation	$ 81.8	$ 83.2
Nonrecourse debt	$ 4.7	$ 6.9