Loans - Summary of Information Pertaining to Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	$ 7,333	$ 3,300
With no related allowance recorded, Contractual Balance	7,584	3,440
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	5,318	5,293
With no related allowance recorded, Interest Income Recognized	150	89
With an allowance recorded, Recorded Investment	9,782	18,013
With an allowance recorded, Contractual Balance	11,724	18,042
With an allowance recorded, Related Allowance	3,955	6,942
With an allowance recorded, Average Recorded Investment	13,899	9,831
With an allowance recorded, Interest Income Recognized	113	459
Total impaired loans, Recorded Investment	17,115	21,313
Total impaired loans, Contractual Balance	19,308	21,482
Total impaired loans, Related Allowance	3,955	6,942
Total impaired loans, Average Recorded Investment	19,217	15,124
Total impaired loans, Interest Income Recognized	263	548
Construction [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment		48
With no related allowance recorded, Contractual Balance		48
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	24	1,146
With no related allowance recorded, Interest Income Recognized		3
With an allowance recorded, Recorded Investment	309	751
With an allowance recorded, Contractual Balance	309	751
With an allowance recorded, Related Allowance	42	176
With an allowance recorded, Average Recorded Investment	530	376
With an allowance recorded, Interest Income Recognized	23	14
Total impaired loans, Recorded Investment	309	799
Total impaired loans, Contractual Balance	309	799
Total impaired loans, Related Allowance	42	176
Total impaired loans, Average Recorded Investment	554	1,522
Total impaired loans, Interest Income Recognized	23	17
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	4,261	1,864
With no related allowance recorded, Contractual Balance	4,469	1,984
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	3,063	2,478
With no related allowance recorded, Interest Income Recognized	110	30
With an allowance recorded, Recorded Investment	5,550	3,339
With an allowance recorded, Contractual Balance	7,428	3,367
With an allowance recorded, Related Allowance	1,639	548
With an allowance recorded, Average Recorded Investment	4,445	1,855
With an allowance recorded, Interest Income Recognized	59	47
Total impaired loans, Recorded Investment	9,811	5,203
Total impaired loans, Contractual Balance	11,897	5,351
Total impaired loans, Related Allowance	1,639	548
Total impaired loans, Average Recorded Investment	7,508	4,333
Total impaired loans, Interest Income Recognized	169	77
Consumer real estate [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	1,973	534
With no related allowance recorded, Contractual Balance	1,999	534
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	1,254	639
With no related allowance recorded, Interest Income Recognized		2
With an allowance recorded, Recorded Investment	1,017	644
With an allowance recorded, Contractual Balance	1,046	644
With an allowance recorded, Related Allowance	183	765
With an allowance recorded, Average Recorded Investment	831	819
With an allowance recorded, Interest Income Recognized	21	9
Total impaired loans, Recorded Investment	2,990	1,178
Total impaired loans, Contractual Balance	3,045	1,178
Total impaired loans, Related Allowance	183	765
Total impaired loans, Average Recorded Investment	2,085	1,458
Total impaired loans, Interest Income Recognized	21	11
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	1,099	854
With no related allowance recorded, Contractual Balance	1,116	874
With no related allowance recorded, Related Allowance
With no related allowance recorded, Average Recorded Investment	977	1,030
With no related allowance recorded, Interest Income Recognized	40	54
With an allowance recorded, Recorded Investment	2,906	13,279
With an allowance recorded, Contractual Balance	2,941	13,280
With an allowance recorded, Related Allowance	2,091	5,453
With an allowance recorded, Average Recorded Investment	8,093	6,781
With an allowance recorded, Interest Income Recognized	10	389
Total impaired loans, Recorded Investment	4,005	14,133
Total impaired loans, Contractual Balance	4,057	14,154
Total impaired loans, Related Allowance	2,091	5,453
Total impaired loans, Average Recorded Investment	9,070	7,811
Total impaired loans, Interest Income Recognized	$ 50	$ 443