REGULATORY CAPITAL REQUIREMENTS (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Total Capital (to risk weighted assets)
Actual, Amount	$ 145,765	$ 128,226
Actual, Ratio (as a percent)	14.20%	16.20%
For Capital Adequacy Purposes, Amount	82,171	63,228
For Capital Adequacy Purposes, Ratio (as a percent)	8.00%	8.00%
Tier 1 Capital (to risk weighted assets)
Actual, Amount	132,906	118,334
Actual, Ratio (as a percent)	12.90%	15.00%
For Capital Adequacy Purposes, Amount	41,085	31,614
For Capital Adequacy Purposes, Ratio (as a percent)	4.00%	4.00%
Tier 1 Capital (to average assets)
Actual, Amount	132,906	118,334
Actual, Ratio (as a percent)	8.40%	9.30%
For Capital Adequacy Purposes, Amount	63,136	51,010
For Capital Adequacy Purposes, Ratio (as a percent)	4.00%	4.00%
Bridgehampton National Bank
Total Capital (to risk weighted assets)
Actual, Amount	140,487	115,383
Actual, Ratio (as a percent)	13.70%	14.60%
For Capital Adequacy Purposes, Amount	82,155	63,213
For Capital Adequacy Purposes, Ratio (as a percent)	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	102,693	79,016
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (as a percent)	10.00%	10.00%
Tier 1 Capital (to risk weighted assets)
Actual, Amount	127,630	105,494
Actual, Ratio (as a percent)	12.40%	13.40%
For Capital Adequacy Purposes, Amount	41,077	31,606
For Capital Adequacy Purposes, Ratio (as a percent)	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	61,616	47,410
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (as a percent)	6.00%	6.00%
Tier 1 Capital (to average assets)
Actual, Amount	127,630	105,494
Actual, Ratio (as a percent)	8.10%	8.30%
For Capital Adequacy Purposes, Amount	63,132	51,001
For Capital Adequacy Purposes, Ratio (as a percent)	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 78,915	$ 63,751
To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (as a percent)	5.00%	5.00%