LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY Loans, Allowance for Loan Losses and Credit Quality (Details 13) (Details) (USD $) In Thousands, unless otherwise specified	Nov. 15, 2013	Nov. 09, 2012	Dec. 31, 2013 Central Bankcorp, Inc. [Member]	Dec. 31, 2012 Central Bankcorp, Inc. [Member]	Nov. 09, 2012 Central Bankcorp, Inc. [Member]	Dec. 31, 2013 Mayflower Bankcorp, Inc. [Member]	Nov. 15, 2013 Mayflower Bankcorp, Inc. [Member]
Outstanding and Carrying Amounts of Purchase Credit Impaired Loans [Line Items]
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Outstanding Balance	$ 3,808	$ 40,799	$ 29,765	$ 36,278		$ 3,790
Less: fair value (initial carrying amount)	$ 2,758	$ 35,720	$ 26,797	$ 32,054	$ 35,720	$ 2,747	$ 2,758

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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