Income Taxes - Additional Information (Detail) |
12 Months Ended |
|---|---|
|
Dec. 31, 2015
USD ($)
| |
| Income Taxes And Tax Related [Line Items] | |
| Unrecognized tax benefits, income tax penalties and interest accrued | $ 0 |
| U.S. [Member] | |
| Income Taxes And Tax Related [Line Items] | |
| Operating tax loss carryforwards, estimated | $ 157,000,000 |
| Operating tax loss carryforwards, estimated expire year | 2035 |
| Tax credit carryforward, amount | $ 1,900,000 |
| Tax credit carryforward, amount expire year | 2035 |
| Adjustments to additional paid in capital, income tax benefit from share-based compensation | $ 0 |
| U.K. [Member] | |
| Income Taxes And Tax Related [Line Items] | |
| Operating tax loss carryforwards, estimated | $ 15,000,000 |