|
Fair Value of Assets and Liabilities - Summary of Liabilities Recorded at Carrying Value (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2015
|
Dec. 31, 2014
|
|---|---|---|
| Fair value and carrying value of the Company's debt instruments | ||
| Current notes payable - Fair value | $ 44.7 | $ 25.6 |
| Notes payable - Carrying value | 44.7 | 25.6 |
| Long-term debt - Fair Value | 538.3 | 483.6 |
| Long-term debt - Carrying value | 534.7 | 479.8 |
| Total debt instruments - Fair value | 583.0 | 509.2 |
| Total debt instruments - Carrying value | $ 579.4 | $ 505.4 |