Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Commitments And Contingencies [Line Items]
Off-balance Sheet Risks, Amount, Liability	$ 381	$ 338
Reserve for sold mortgages	273
Notional amount of RPAs	12,000
Negative fair value of RPAs	965
Interest-earning deposit accounts pledged for Risk Participation Agreements	10
Approximate payment required in event of default of RPAs	965
Fair value of risk participation agreement guarantee	68
Future Rental Income Receivable Under Subleases	149
Letter of Credit [Member]
Commitments And Contingencies [Line Items]
Current carrying amount of the contingent obligation	$ 450
Minimum [Member]
Commitments And Contingencies [Line Items]
Term of letter of credit	1 year
Terms of the underlying swaps	10 years
Maximum [Member]
Commitments And Contingencies [Line Items]
Term of letter of credit	5 years
Terms of the underlying swaps	13 years
Maximum [Member] | Letter of Credit [Member]
Commitments And Contingencies [Line Items]
Off-balance Sheet Risks, Amount, Liability	$ 57,600