Stockholders' Equity - Warrants (Details) - Warrants (Note 6) - $ / shares |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2019 |
Dec. 31, 2018 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Number of Warrants, Outstanding Beginning Balance | 4,280,972 | |
| Number of Warrants, Exercised | (47,379) | |
| Number of Warrants, Outstanding Ending Balance | 4,233,593 | 4,280,972 |
| Weighted Average Exercise Price, Nonvested Beginning Balance | $ 6.69 | |
| Weighted Average Grant Date Fair Value, Vested | 0 | |
| Weighted Average Exercise Price, Nonvested Ending Balance | $ 6.77 | $ 6.69 |
| Weighted Average Remaining Contractual Life, Outstanding (in years) | 1 year 9 months 11 days | 2 years 3 months 29 days |
| X | ||||||||||
- Definition Number of warrants or rights outstanding. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Number of non-option equity instruments exercised by participants. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|