Financial Instruments with Off-Balance-Sheet Risk - Additional Information (Detail) $ in Millions |
Dec. 31, 2015
USD ($)
|
---|---|
Commitments to Extend Credit [Member] | |
Other Commitments [Line Items] | |
Off balance sheet risk financial instruments | $ 176.8 |
Standby and commercial Letters of Credit [Member] | |
Other Commitments [Line Items] | |
Off balance sheet risk financial instruments | $ 9.2 |