Loans - Pre-Modification and Post-Modification Outstanding Recorded Investments (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) Contract	Jun. 30, 2014 USD ($) Contract	Jun. 30, 2015 USD ($) Contract	Jun. 30, 2014 USD ($) Contract
Accounts, Notes, Loans and Financing Receivable
Number of Contracts | Contract	13	12	21	25
Pre-Modification Outstanding Recorded Investment	$ 6,188	$ 5,072	$ 13,052	$ 32,519
Post-Modification Outstanding Recorded Investment	$ 6,861	$ 5,041	$ 13,627	$ 30,934
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Number of Contracts | Contract	6	3	12	7
Pre-Modification Outstanding Recorded Investment	$ 1,947	$ 1,469	$ 3,531	$ 7,682
Post-Modification Outstanding Recorded Investment	$ 1,922	$ 1,469	$ 3,412	$ 7,056
Commercial real estate
Accounts, Notes, Loans and Financing Receivable
Number of Contracts | Contract	3	3	4	10
Pre-Modification Outstanding Recorded Investment	$ 1,562	$ 689	$ 6,562	$ 16,596
Post-Modification Outstanding Recorded Investment	$ 1,573	$ 710	$ 6,573	$ 15,641
Construction
Accounts, Notes, Loans and Financing Receivable
Number of Contracts | Contract	1	1	1	3
Pre-Modification Outstanding Recorded Investment	$ 500	$ 457	$ 500	$ 5,784
Post-Modification Outstanding Recorded Investment	$ 1,190	$ 457	$ 1,190	$ 5,782
Total commercial real estate loans
Accounts, Notes, Loans and Financing Receivable
Number of Contracts | Contract	4	4	5	13
Pre-Modification Outstanding Recorded Investment	$ 2,062	$ 1,146	$ 7,062	$ 22,380
Post-Modification Outstanding Recorded Investment	$ 2,763	$ 1,167	$ 7,763	$ 21,423
Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Number of Contracts | Contract	2	4	3	4
Pre-Modification Outstanding Recorded Investment	$ 1,098	$ 2,325	$ 1,378	$ 2,325
Post-Modification Outstanding Recorded Investment	$ 1,097	$ 2,273	$ 1,373	$ 2,323
Consumer
Accounts, Notes, Loans and Financing Receivable
Number of Contracts | Contract	1	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 1,081	$ 132	$ 1,081	$ 132
Post-Modification Outstanding Recorded Investment	$ 1,079	$ 132	$ 1,079	$ 132