Regulatory Matters - Actual Capital Amounts and Ratios of Bank (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Minimum to be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 201,201	$ 188,495
Tier 1 Capital (to Risk Weighted Assets), Minimum to be Well Capitalized Under Prompt Corrective Action Provisions, Amount	120,720	113,097
Tier 1 Capital (to Average Assets), Minimum to be Well Capitalized Under Prompt Corrective Action Provisions, Amount	133,706	127,333
Total Capital (to Risk Weighted Assets), Minimum to be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum to be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.00%	6.00%
Tier 1 Capital (to Average Assets), Minimum to be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%
Parent [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Actual, Amount	297,429	273,979
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	272,071	250,133
Tier 1 Capital (to Average Assets), Actual, Amount	272,071	250,133
Total Capital (to Risk Weighted Assets), Actual, Ratio	14.77%	14.53%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.51%	13.27%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.17%	9.82%
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	161,064	150,896
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	80,532	75,448
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	107,017	101,918
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	8.00%	8.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Tri Countries Bank [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Actual, Amount	295,212	271,723
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	269,870	247,892
Tier 1 Capital (to Average Assets), Actual, Amount	269,870	247,892
Total Capital (to Risk Weighted Assets), Actual, Ratio	14.67%	14.42%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.41%	13.16%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.09%	9.73%
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	160,961	150,796
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	80,480	75,398
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 106,965	$ 101,866
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	8.00%	8.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%