Debt - Credit Facilities - Commitments, Amounts Outstanding, and Amounts Available (Details) $ in Millions	Dec. 31, 2015 USD ($)
Line of Credit Facility [Line Items]
Total Commitments	$ 1,442.2
Total Outstanding	237.4
Total Available	1,181.1
Standby letters of credit issued	23.7
Senior Secured Domestic Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Commitments	1,250.0
Total Outstanding	149.6
Total Available	1,076.7
Senior Secured International Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Commitments	170.7
Total Outstanding	75.2
Total Available	95.5
Other International Facilities
Line of Credit Facility [Line Items]
Total Commitments	21.5
Total Outstanding	12.6
Total Available	$ 8.9