Regulatory Matters - Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
The Bank of Greene County [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk weighted assets), Amount	$ 63,918	$ 58,892
Total capital (to risk weighted assets) For Capital Adequacy Purposes, Amount	27,600	25,424
Total capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	34,499	31,780
Total capital (to risk weighted assets), Ratio (in hundredths)	18.50%	18.50%
Total capital (to risk weighted assets) For Capital Adequacy Purposes, Ratio (in hundredths)	8.00%	8.00%
Total capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (in hundredths)	10.00%	10.00%
Tier 1 capital (to risk weighted assets), Amount	59,523	54,843
Tier 1 capital (to risk weighted assets) For Capital Adequacy Purposes, Amount	13,800	12,712
Tier 1 capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	20,700	19,068
Tier 1 capital (to risk weighted assets), Ratio (in hundredths)	17.30%	17.30%
Tier 1 capital (to risk weighted assets) For Capital Adequacy Purposes, Ratio (in hundredths)	4.00%	4.00%
Tier 1 capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (in hundredths)	6.00%	6.00%
Tier 1 capital (to average assets), Amount	59,523	54,843
Tier 1 capital (to average assets) For Capital Adequacy Purposes, Amount	20,257	19,050
Tier 1 capital (to average assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	33,761	31,751
Tier 1 capital (to average assets), Ratio (in hundredths)	8.80%	8.60%
Tier 1 capital (to average assets) For Capital Adequacy Purposes, Ratio (in hundredths)	3.00%	3.00%
Tier 1 capital (to average assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (in hundredths)	5.00%	5.00%
Greene County Commercial Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk weighted assets), Amount	17,211	15,256
Total capital (to risk weighted assets) For Capital Adequacy Purposes, Amount	3,388	3,091
Total capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	4,236	3,864
Total capital (to risk weighted assets), Ratio (in hundredths)	40.60%	39.50%
Total capital (to risk weighted assets) For Capital Adequacy Purposes, Ratio (in hundredths)	8.00%	8.00%
Total capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (in hundredths)	10.00%	10.00%
Tier 1 capital (to risk weighted assets), Amount	17,211	15,256
Tier 1 capital (to risk weighted assets) For Capital Adequacy Purposes, Amount	1,694	1,546
Tier 1 capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	2,541	2,318
Tier 1 capital (to risk weighted assets), Ratio (in hundredths)	40.60%	39.50%
Tier 1 capital (to risk weighted assets) For Capital Adequacy Purposes, Ratio (in hundredths)	4.00%	4.00%
Tier 1 capital (to risk weighted assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (in hundredths)	6.00%	6.00%
Tier 1 capital (to average assets), Amount	17,211	15,256
Tier 1 capital (to average assets) For Capital Adequacy Purposes, Amount	8,369	7,912
Tier 1 capital (to average assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 10,461	$ 9,890
Tier 1 capital (to average assets), Ratio (in hundredths)	8.20%	7.70%
Tier 1 capital (to average assets) For Capital Adequacy Purposes, Ratio (in hundredths)	4.00%	4.00%
Tier 1 capital (to average assets) To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio (in hundredths)	5.00%	5.00%