Summary of Significant Accounting Policies (Details 3) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2015
USD ($)
segment
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2013
USD ($)
|
|
| Planned Major Maintenance Costs | |||
| Turnaround costs | $ 7.0 | ||
| Cost Classifications | |||
| Depreciation expense incurred related to the cost of product sold | 0.6 | $ 0.4 | $ 0.3 |
| Depreciation and amortization not included in direct operating expenses | $ 27.8 | $ 26.8 | $ 25.3 |
| Segment Reporting | |||
| Number of operating segments | segment | 1 | ||
| Revenue Recognition | |||
| Expected period of delivery of deferred revenue | 12 months | ||
| Minimum | |||
| Planned Major Maintenance Costs | |||
| Frequency of planned major maintenance activities | 2 years | ||
| Maximum | |||
| Planned Major Maintenance Costs | |||
| Frequency of planned major maintenance activities | 3 years | ||