Intangible Assets and Goodwill - Additional Information (Detail) - USD ($) |
6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2016 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Goodwill And Intangible Assets Disclosure [Abstract] | ||||
| Intangible assets and goodwill impairment | $ 0 | |||
| Amortization expense | $ 51,000 | $ 63,000 | $ 69,000 | |