Regulatory Matters (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Jun. 30, 2014
The Bank of Greene County [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital, amount	$ 71,572	$ 63,918
Total risk-based capital for capital adequacy purposes, amount	32,082	27,600
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 40,102	$ 34,499
Total risk-based capital, ratio (in hundredths)	17.90%	18.50%
Total risk-based capital for capital adequacy purposes, ratio (in hundredths)	8.00%	8.00%
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio (in hundredths)	10.00%	10.00%
Tier 1 risk-based capital, amount	$ 66,487	$ 59,523
Tier 1 risk-based capital for capital adequacy purposes, amount	24,061	13,800
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 32,082	$ 20,700
Tier 1 risk-based capital, ratio (in hundredths)	16.60%	17.30%
Tier 1 risk-based capital for capital adequacy purposes, ratio (in hundredths)	6.00%	4.00%
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio (in hundredths)	8.00%	6.00%
Common equity tier 1 capital, amount	$ 66,487
Common equity tier 1 capital for capital adequacy purposes, amount	18,046
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, amount	$ 26,066
Common equity tier 1 capital, ratio (in hundredths)	16.60%
Common equity tier 1 capital for capital adequacy purposes, ratio (in hundredths)	4.50%
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, ratio (in hundredths)	6.50%
Tier 1 leverage ratio, amount	$ 66,487	$ 59,523
Tier 1 leverage ratio for capital adequacy purposes, amount	29,256	20,257
Tier 1 leverage ratio to be well capitalized under prompt corrective action provisions, amount	$ 36,571	$ 33,761
Tier 1 leverage ratio, ratio (in hundredths)	9.10%	8.80%
Tier 1 leverage ratio for capital adequacy purposes, ratio (in hundredths)	4.00%	3.00%
Tier 1 leverage ratio 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 risk-based capital, amount	$ 19,853	$ 17,211
Total risk-based capital for capital adequacy purposes, amount	3,526	3,388
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 4,408	$ 4,236
Total risk-based capital, ratio (in hundredths)	45.04%	40.60%
Total risk-based capital for capital adequacy purposes, ratio (in hundredths)	8.00%	8.00%
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio (in hundredths)	10.00%	10.00%
Tier 1 risk-based capital, amount	$ 19,853	$ 17,211
Tier 1 risk-based capital for capital adequacy purposes, amount	2,645	1,694
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 3,526	$ 2,541
Tier 1 risk-based capital, ratio (in hundredths)	45.04%	40.60%
Tier 1 risk-based capital for capital adequacy purposes, ratio (in hundredths)	6.00%	4.00%
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio (in hundredths)	8.00%	6.00%
Common equity tier 1 capital, amount	$ 19,853
Common equity tier 1 capital for capital adequacy purposes, amount	1,984
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, amount	$ 2,865
Common equity tier 1 capital, ratio (in hundredths)	45.04%
Common equity tier 1 capital for capital adequacy purposes, ratio (in hundredths)	4.50%
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, ratio (in hundredths)	6.50%
Tier 1 leverage ratio, amount	$ 19,853	$ 17,211
Tier 1 leverage ratio for capital adequacy purposes, amount	8,796	8,369
Tier 1 leverage ratio to be well capitalized under prompt corrective action provisions, amount	$ 10,995	$ 10,461
Tier 1 leverage ratio, ratio (in hundredths)	9.03%	8.20%
Tier 1 leverage ratio for capital adequacy purposes, ratio (in hundredths)	4.00%	4.00%
Tier 1 leverage ratio to be well capitalized under prompt corrective action provisions, ratio (in hundredths)	5.00%	5.00%