Commitments and Contingencies Commitments and Contingencies, Changes in Environmental Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Loss Contingency, Range of Possible Loss, Portion Not Accrued	$ 12.3			$ 12.3	$ 24.7
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	18.6	$ 19.3	$ 22.8
Additional accruals	0.1	1.3	0.8
Less expenditures	1.5	2.0	4.3
Ending balance	$ 17.2	$ 18.6	$ 19.3