Long-term Debt (Details) - USD ($) $ in Millions |
Sep. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Debt Instrument [Line Items] | ||
| Amounts borrowed | $ 274.1 | $ 60.4 |
| Revolving Credit Facility | ||
| Debt Instrument [Line Items] | ||
| Amounts borrowed | 262.0 | 47.0 |
| Outstanding letters of credit and other commitments | 37.3 | 18.5 |
| Amounts available to borrow | 150.7 | 123.9 |
| Obligations under capital leases | ||
| Debt Instrument [Line Items] | ||
| Amounts borrowed | $ 12.1 | $ 13.4 |