Financial Instruments with Off Balance Sheet Risk - Schedule of Bank's Exposure to Credit Loss (Detail) - USD ($) $ in Thousands |
Sep. 30, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contract or Notional Amount | $ 50,868 | $ 53,316 |
| Commitments to Grant Loans [Member] | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contract or Notional Amount | 21,207 | 17,046 |
| Unfunded Commitments of Existing Loans [Member] | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contract or Notional Amount | 26,362 | 33,603 |
| Standby and Performance Letters of Credit [Member] | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contract or Notional Amount | $ 3,299 | $ 2,667 |