GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2013	Dec. 31, 2014	Nov. 15, 2013	Nov. 09, 2012
Goodwill [Roll Forward]
Balance at beginning of year	$ 130,074			$ 170,421
Impairment	(2,227)	[1]
Balance at end of year	150,391		170,421	170,421
Mayflower Bankcorp, Inc. [Member]
Goodwill [Roll Forward]
Balance at beginning of year					20,030
Acquisitions	22,544
Balance at end of year					20,030
Central Bankcorp, Inc. [Member]
Goodwill [Roll Forward]
Balance at beginning of year						22,544
Acquisitions			20,030
Balance at end of year						$ 22,544

[1] Amount represents the total amount of goodwill relating to Compass Exchange Advisors, LLC, which was acquired in January 2007.