Commitments and Contingencies - Schedule of Off-balance-sheet Credit Risks (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet credit risk liability	$ 134,104	$ 155,551
Commitments to Grant Loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet credit risk liability	20,380	63,607
Unadvanced Funds on Lines of Credit | Home equity:
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet credit risk liability	35,718	34,498
Unadvanced Funds on Lines of Credit | Personal Line of Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet credit risk liability	1,828	1,852
Unadvanced Funds on Lines of Credit | Commercial Line of Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet credit risk liability	37,789	29,882
Unadvanced Funds on Loans | Construction Loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet credit risk liability	37,889	25,164
Standby Letters of Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet credit risk liability	$ 500	$ 548