Non-performing Assets and Impaired Loans - Commercial Loans Individually Evaluated for Impairment by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Financial Receivables [Line Items]
Unpaid Principal Balance total	$ 7,426	$ 10,597	$ 7,958
Total ending loans balance	7,448	10,627	7,960
Allowance For Loan Loss Allocated	1,312	1,945	2,136
Average Balance in Impaired Loans total	7,336	6,137	4,841
Cash/Accrual Interest Income Recognized, Total	271	201	181
Commercial [Member]
Schedule Of Financial Receivables [Line Items]
Unpaid Principal Balance With no recorded allowance	5,227	7,433	1,632
Recorded Investment With no recorded allowance	5,249	7,463	1,634
Allowance For Loan Loss Allocated With no recorded allowance
Average Balance in Impaired Loans With no recorded allowance	5,545	4,324	1,261
Cash/Accrual Interest Income Recognized, With no recorded allowance	240	100	51
Unpaid Principal Balance With an allowance recorded	2,199	3,164	6,326
Recorded Investment With an allowance recorded	2,199	3,164	6,326
Allowance For Loan Loss Allocated	1,312	1,945	2,136
Average Balance in Impaired Loans With an allowance recorded	1,791	1,813	3,580
Cash/Accrual Interest Income Recognized, With an allowance recorded	31	101	130
Commercial [Member] | Owner Occupied Real Estate [Member]
Schedule Of Financial Receivables [Line Items]
Unpaid Principal Balance With no recorded allowance	1,293	4,890	192
Recorded Investment With no recorded allowance	1,296	4,901	192
Allowance For Loan Loss Allocated With no recorded allowance
Average Balance in Impaired Loans With no recorded allowance	1,845	2,422	110
Cash/Accrual Interest Income Recognized, With no recorded allowance	68	80	2
Unpaid Principal Balance With an allowance recorded			2,323
Recorded Investment With an allowance recorded			2,323
Allowance For Loan Loss Allocated			770
Average Balance in Impaired Loans With an allowance recorded			1,911
Cash/Accrual Interest Income Recognized, With an allowance recorded			25
Commercial [Member] | Non-owner Occupied Real Estate [Member]
Schedule Of Financial Receivables [Line Items]
Unpaid Principal Balance With no recorded allowance	3,521	1,961	954
Recorded Investment With no recorded allowance	3,525	1,963	956
Allowance For Loan Loss Allocated With no recorded allowance
Average Balance in Impaired Loans With no recorded allowance	2,963	1,544	639
Cash/Accrual Interest Income Recognized, With no recorded allowance	172	20	43
Unpaid Principal Balance With an allowance recorded	403	1,795	3,168
Recorded Investment With an allowance recorded	403	1,795	3,168
Allowance For Loan Loss Allocated	202	1,080	1,080
Average Balance in Impaired Loans With an allowance recorded	485	481	830
Cash/Accrual Interest Income Recognized, With an allowance recorded		95	83
Commercial [Member] | Residential Development [Member]
Schedule Of Financial Receivables [Line Items]
Unpaid Principal Balance With no recorded allowance
Recorded Investment With no recorded allowance
Allowance For Loan Loss Allocated With no recorded allowance
Average Balance in Impaired Loans With no recorded allowance
Cash/Accrual Interest Income Recognized, With no recorded allowance
Unpaid Principal Balance With an allowance recorded
Recorded Investment With an allowance recorded
Allowance For Loan Loss Allocated
Average Balance in Impaired Loans With an allowance recorded
Cash/Accrual Interest Income Recognized, With an allowance recorded
Commercial [Member] | Development & Spec Land Loans [Member]
Schedule Of Financial Receivables [Line Items]
Unpaid Principal Balance With no recorded allowance	23	133	90
Recorded Investment With no recorded allowance	23	133	90
Allowance For Loan Loss Allocated With no recorded allowance
Average Balance in Impaired Loans With no recorded allowance	25	61	157
Cash/Accrual Interest Income Recognized, With no recorded allowance
Unpaid Principal Balance With an allowance recorded	159	572
Recorded Investment With an allowance recorded	159	572
Allowance For Loan Loss Allocated	48	600
Average Balance in Impaired Loans With an allowance recorded	166	526
Cash/Accrual Interest Income Recognized, With an allowance recorded		6
Commercial [Member] | Commercial and Industrial [Member]
Schedule Of Financial Receivables [Line Items]
Unpaid Principal Balance With no recorded allowance	390	449	396
Recorded Investment With no recorded allowance	405	466	396
Allowance For Loan Loss Allocated With no recorded allowance
Average Balance in Impaired Loans With no recorded allowance	712	297	355
Cash/Accrual Interest Income Recognized, With no recorded allowance			6
Unpaid Principal Balance With an allowance recorded	1,637	797	835
Recorded Investment With an allowance recorded	1,637	797	835
Allowance For Loan Loss Allocated	1,062	265	286
Average Balance in Impaired Loans With an allowance recorded	1,140	806	839
Cash/Accrual Interest Income Recognized, With an allowance recorded	$ 31		$ 22