Troubled Debt Restructuring (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) Contracts	Sep. 30, 2014 USD ($) Contracts	Sep. 30, 2015 USD ($) Contracts	Sep. 30, 2014 USD ($) Contracts
Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	2	0	2	0
Pre- Modification Outstanding Recorded Investment	$ 40	$ 0	$ 40	$ 0
Post-Modification Outstanding Recorded Investment	40	0	40	0
Interest Only	0	0	0	0
Term	40	0	40	0
Combination	0	0	0	0
Total Modification	$ 40	$ 0	$ 40	$ 0
Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	1	0	1	2
Pre- Modification Outstanding Recorded Investment	$ 62	$ 0	$ 62	$ 155
Post-Modification Outstanding Recorded Investment	62	0	62	68
Interest Only	0	0	0	0
Term	62	0	62	68
Combination	0	0	0	0
Total Modification	$ 62	$ 68	$ 62	$ 68
Residential
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	0	0	0	0
Pre- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	0	0	0	0
Interest Only	0	0	0	0
Term	0	0	0	0
Combination	0	0	0	0
Total Modification	$ 0	$ 0	$ 0	$ 0
Installment
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	0	0	0	0
Pre- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	0	0	0	0
Consumer
Financing Receivable, Modifications [Line Items]
Interest Only	0	0	0	0
Term	0	0	0	0
Combination	0	0	0	0
Total Modification	$ 0	$ 0	$ 0	$ 0