Minimum Regulatory Capital Requirements - Schedule of Regulatory Capital Amounts and Ratios (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Capital [Abstract]
Total capital (to risk weighted assets), actual, amount	$ 92,586	$ 88,670
Total capital (to risk weighted assets), minimum for capital adequacy purposes, amount	40,547	37,077
Tier One Leverage Capital [Abstract]
Tier 1 capital (to average assets), actual, amount	86,922	83,248
Tier 1 capital (to average assets), minimum for capital adequacy purposes, amount	28,420	26,240
Risk Based Ratios [Abstract]
Total capital (to risk weighted assets), actual, ratio	18.30%	19.10%
Total capital (to risk weighted assets), minimum for capital adequacy purposes, ratio	8.00%	8.00%
Tier 1 capital (to risk weighted assets), actual, ratio	17.20%	18.00%
Tier 1 capital (to risk weighted assets), minimum for capital adequacy purposes, ratio	4.00%	4.00%
Leverage Ratios [Abstract]
Tier 1 capital (to average assets), actual, ratio	12.20%	12.70%
Tier 1 capital (to average assets), minimum for capital adequacy purposes, ratio	4.00%	4.00%
Tier One Risk Based Capital [Abstract]
Tier 1 capital (to risk weighted assets), actual, amount	86,922	83,248
Tier 1 capital (to risk weighted assets), minimum for capital adequacy purposes, amount	20,273	18,538
Hampden Bank
Capital [Abstract]
Total capital (to risk weighted assets), actual, amount	80,715	80,350
Total capital (to risk weighted assets), minimum for capital adequacy purposes, amount	40,570	36,788
Total capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions, amount	50,712	45,985
Tier One Leverage Capital [Abstract]
Tier 1 capital (to average assets), actual, amount	75,051	74,928
Tier 1 capital (to average assets), minimum for capital adequacy purposes, amount	28,297	25,827
Tier 1 capital (to average assets), minimum to be well capitalized under prompt corrective action provisions, amount	35,372	32,284
Risk Based Ratios [Abstract]
Total capital (to risk weighted assets), actual, ratio	15.90%	17.50%
Total capital (to risk weighted assets), minimum for capital adequacy purposes, ratio	8.00%	8.00%
Tier 1 capital (to risk weighted assets), actual, ratio	14.80%	16.30%
Tier 1 capital (to risk weighted assets), minimum for capital adequacy purposes, ratio	4.00%	4.00%
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%
Leverage Ratios [Abstract]
Tier 1 capital (to average assets), actual, ratio	10.60%	11.60%
Tier 1 capital (to average assets), minimum for capital adequacy purposes, ratio	4.00%	4.00%
Tier 1 capital (to average assets), minimum to be well capitalized under prompt corrective action provisions, ratio	5.00%	5.00%
Tier One Risk Based Capital [Abstract]
Tier 1 capital (to risk weighted assets), actual, amount	75,051	74,928
Tier 1 capital (to risk weighted assets), minimum for capital adequacy purposes, amount	20,285	18,394
Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions, amount	$ 30,427	$ 27,591