Commitments and Contingencies (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Estimated Litigation Liability	$ 0.0	$ 0.0
Letters of Credit Outstanding, Amount	3.6
Surety Bond [Member]
Loss Contingencies [Line Items]
Outstanding surety bonds	19.2	$ 12.2
Letter of Credit [Member]
Loss Contingencies [Line Items]
Letter of Credit Facility, Maximum Borrowing Capacity	5.0
Optional Facility Increase [Member] | Letter of Credit [Member]
Loss Contingencies [Line Items]
Letter of Credit Facility, Maximum Borrowing Capacity	$ 7.5