Loans - Summary of Period Ending Balances of Newly Restructured Loans and Types of Modifications (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Rate	$ 550	$ 1,677	$ 16,055
Rate & Maturity	6,395	966	43
Rate & Payment Deferral	539	367
Maturity	7,011	2,942
Payment Deferral	2,129	1,584	2,137
Total	16,624	7,536	18,235
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Rate	0	0	5,329
Rate & Maturity	0	17	0
Rate & Payment Deferral	0	0
Maturity	6,093	104
Payment Deferral	0	453	49
Total	6,093	574	5,378
Commercial real estate: Other [Member]
Financing Receivable, Modifications [Line Items]
Rate	0	0	6,206
Rate & Maturity	6,029	740	0
Rate & Payment Deferral	0	0
Maturity	918	2,838
Payment Deferral	2,129	1,131	2,088
Total	9,076	4,709	8,294
Residential: 1-4 family [Member]
Financing Receivable, Modifications [Line Items]
Rate	550	1,622	4,223
Rate & Maturity	205	0	43
Rate & Payment Deferral	539	367
Maturity	0	0
Payment Deferral	0	0	0
Total	1,294	1,989	4,266
Residential: Home equities [Member]
Financing Receivable, Modifications [Line Items]
Rate	0	55	297
Rate & Maturity	161	209	0
Rate & Payment Deferral	0	0
Maturity	0	0
Payment Deferral	0	0	0
Total	$ 161	$ 264	$ 297