Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|---|
| Deferred tax assets | |||
| Accrued expenses and other current liabilities | $ 1,065,000 | $ 1,147,000 | |
| Business credits | 2,913,000 | 1,962,000 | |
| Stock-based compensation | 4,393,000 | 2,488,000 | |
| Net operating loss carryover | 21,151,000 | 13,586,000 | |
| Other | 1,253,000 | 358,000 | |
| Total deferred tax assets | 30,775,000 | 19,541,000 | |
| Less: valuation allowance | (8,489,000) | (887,000) | $ 0 |
| Deferred tax assets, net of valuation allowance | 22,286,000 | 18,654,000 | |
| Deferred tax liabilities | |||
| Property and equipment | (1,250,000) | (1,473,000) | |
| Common stock warrants | (63,000) | ||
| Intangible assets | (20,439,000) | (21,800,000) | |
| Prepaid expenses | (1,859,000) | (1,225,000) | |
| Total deferred tax liabilities | (23,548,000) | (24,561,000) | |
| Net deferred taxes | $ (1,262,000) | $ (5,907,000) |