Income Taxes - Additional Information (Detail) - USD ($) |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Income Tax [Line Items] | |||
Operating loss carryforwards, latest expiration year | 2037 | ||
Operating loss carryforwards, expiration date | various years through 2037 | ||
Operating loss carryforwards | $ 64,904,000 | $ 62,655,000 | |
Increase in operating loss carryforwards | 2,249,000 | ||
Net deferred tax asset recognized | $ 0 | ||
Change period for unrecognized tax benefits | 12 months | ||
Net decrease in deferred tax assets | $ 8,819,000 | ||
Increase in deferred tax assets | 724,000 | ||
Tax cuts and jobs act of 2017, Change in tax rate in decrease in deferred tax assets | $ 9,543,000 | ||
Statutory federal income tax rate | 35.00% | 35.00% | |
Scenario Plan [Member] | |||
Income Tax [Line Items] | |||
Statutory federal income tax rate | 21.00% |