Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Current:    
Accrued expenses $ 882 $ 754
Valuation allowance (642) (552)
Total current deferred tax asset 240 202
Long-term:    
Stock-based compensation 854 360
Future benefit of carry forward losses 17,946 9,961
Other accruals 488 160
Valuation allowance (14,229) (7,740)
Total long-term deferred tax asset 5,059 2,741
Current:    
Other accruals (20) (19)
Total current deferred tax liability (20) (19)
Long-term:    
Amortization (3,688) (2,090)
Depreciation (1,591) (814)
Other accruals 0 (20)
Total long-term deferred tax liability (5,279) (2,924)
Net deferred tax assets (liabilities) $ 0 $ 0