Debt - Components of Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Total current debt	$ 27,806	$ 33,000
Total long-term debt	20,931	0
Total debt	48,737	33,000
Senior Credit Facility
Debt Instrument [Line Items]
Total long-term debt	14,592	0
Letters of credit issued	$ 21,500	$ 10,700
Weighted average interest rate on current portion of debt	3.90%	4.03%
Convertible Subordinated Notes
Debt Instrument [Line Items]
Total long-term debt	$ 6,339	$ 0
Convertible Subordinated Notes | Oasis Note
Debt Instrument [Line Items]
Unamortized discount	700
Senior Credit Facility | Working Capital Line
Debt Instrument [Line Items]
Total current debt	22,500	33,000
Senior Credit Facility | Acquisition Line
Debt Instrument [Line Items]
Total current debt	$ 5,306	$ 0