Regulatory Matters (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015
The Bank of Greene County [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital, actual amount	$ 76,666	$ 71,572
Total risk-based capital, actual ratio	16.30%	17.90%
Total risk-based capital for capital adequacy purposes, amount	$ 37,577	$ 32,082
Total risk-based capital for capital adequacy purposes, ratio	8.00%	8.00%
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 46,972	$ 40,102
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio	10.00%	10.00%
Total risk-based capital for capital conservation buffer, actual	8.322%	0.00%
Total risk-based capital for capital conservation buffer, required	0.625%	0.00%
Tier 1 risk-based capital, actual amount	$ 70,709	$ 66,487
Tier 1 risk-based capital, actual ratio	15.10%	16.60%
Tier 1 risk-based capital for capital adequacy purposes, amount	$ 28,183	$ 24,061
Tier 1 risk-based capital for capital adequacy purposes, ratio	6.00%	6.00%
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 37,577	$ 32,082
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio	8.00%	8.00%
Tier 1 risk-based capital for capital conservation buffer, actual	9.054%	0.00%
Tier 1 risk-based capital for capital conservation buffer, required	0.625%	0.00%
Common equity tier 1 capital, actual amount	$ 70,709	$ 66,487
Common equity tier 1 capital, actual ratio	15.10%	16.60%
Common equity tier 1 capital for capital adequacy purposes, amount	$ 21,137	$ 18,046
Common equity tier 1 capital for capital adequacy purposes, ratio	4.50%	4.50%
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, amount	$ 30,532	$ 26,066
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, ratio	6.50%	6.50%
Common equity tier 1 capital for capital conservation buffer, actual	10.554%	0.00%
Common equity tier 1 capital for capital conservation buffer, required	0.625%	0.00%
Tier 1 leverage ratio, actual amount	$ 70,709	$ 66,487
Tier 1 leverage ratio, actual ratio	8.40%	9.10%
Tier 1 leverage ratio for capital adequacy purposes, amount	$ 33,815	$ 29,256
Tier 1 leverage ratio for capital adequacy purposes, ratio	4.00%	4.00%
Tier 1 leverage ratio to be well capitalized under prompt corrective action provisions, amount	$ 42,268	$ 36,571
Tier 1 leverage ratio to be well capitalized under prompt corrective action provisions, ratio	5.00%	5.00%
Tier 1 leverage ratio for capital conservation buffer, actual	4.364%	0.00%
Tier 1 leverage ratio for capital conservation buffer, required	0.625%	0.00%
Greene County Commercial Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital, actual amount	$ 23,065	$ 19,853
Total risk-based capital, actual ratio	40.80%	45.00%
Total risk-based capital for capital adequacy purposes, amount	$ 4,518	$ 3,526
Total risk-based capital for capital adequacy purposes, ratio	8.00%	8.00%
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 5,648	$ 4,408
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio	10.00%	10.00%
Total risk-based capital for capital conservation buffer, actual	32.84%	0.00%
Total risk-based capital for capital conservation buffer, required	0.625%	0.00%
Tier 1 risk-based capital, actual amount	$ 23,065	$ 19,853
Tier 1 risk-based capital, actual ratio	40.80%	45.00%
Tier 1 risk-based capital for capital adequacy purposes, amount	$ 3,389	$ 2,645
Tier 1 risk-based capital for capital adequacy purposes, ratio	6.00%	6.00%
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount	$ 4,518	$ 3,526
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio	8.00%	8.00%
Tier 1 risk-based capital for capital conservation buffer, actual	34.84%	0.00%
Tier 1 risk-based capital for capital conservation buffer, required	0.625%	0.00%
Common equity tier 1 capital, actual amount	$ 23,065	$ 19,853
Common equity tier 1 capital, actual ratio	40.80%	45.00%
Common equity tier 1 capital for capital adequacy purposes, amount	$ 2,541	$ 1,984
Common equity tier 1 capital for capital adequacy purposes, ratio	4.50%	4.50%
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, amount	$ 3,671	$ 2,865
Common equity tier 1 capital to be well capitalized under prompt corrective action provisions, ratio	6.50%	6.50%
Common equity tier 1 capital for capital conservation buffer, actual	36.34%	0.00%
Common equity tier 1 capital for capital conservation buffer, required	0.625%	0.00%
Tier 1 leverage ratio, actual amount	$ 23,065	$ 19,853
Tier 1 leverage ratio, actual ratio	8.10%	9.00%
Tier 1 leverage ratio for capital adequacy purposes, amount	$ 11,409	$ 8,796
Tier 1 leverage ratio for capital adequacy purposes, ratio	4.00%	4.00%
Tier 1 leverage ratio to be well capitalized under prompt corrective action provisions, amount	$ 14,262	$ 10,995
Tier 1 leverage ratio to be well capitalized under prompt corrective action provisions, ratio	5.00%	5.00%
Tier 1 leverage ratio for capital conservation buffer, actual	4.086%	0.00%
Tier 1 leverage ratio for capital conservation buffer, required	0.625%	0.00%