Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Movement in Valuation Allowances and Reserves [Roll Forward] | ||
| Balance, beginning of period | $ 232 | $ 294 |
| Deductions | (2,675) | (2,967) |
| Balance, end of period | 219 | 232 |
| Deferred Tax Valuation Allowance [Member] | ||
| Movement in Valuation Allowances and Reserves [Roll Forward] | ||
| Balance, beginning of period | 11,373 | 12,938 |
| Charged to Income | 1,189 | (1,565) |
| Deductions | 0 | 0 |
| Other | 0 | 0 |
| Balance, end of period | $ 12,562 | $ 11,373 |