Commitments (Details) $ in Millions	Sep. 30, 2015 USD ($)
Other Commitments [Line Items]
Letters of Credit Outstanding, Amount	$ 68.2
Revolving Credit Facility [Member]
Other Commitments [Line Items]
Letters of Credit Outstanding, Amount	42.7
Cash and Cash Equivalents [Member]
Other Commitments [Line Items]
Pledged Assets, Not Separately Reported, Other	3.1
Guarantee Type, Other [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	15.0
Performance Guarantee [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	24.3
Indemnification Agreement [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 450.0