ACQUISITIONS (Details 1) (USD $) In Thousands, unless otherwise specified							12 Months Ended			12 Months Ended
	Dec. 31, 2013	Nov. 15, 2013	Dec. 31, 2012	Nov. 09, 2012		Dec. 31, 2011	Dec. 31, 2013 Mayflower Bankcorp, Inc. [Member]	Dec. 31, 2012 Mayflower Bankcorp, Inc. [Member]	Nov. 15, 2013 Mayflower Bankcorp, Inc. [Member]	Dec. 31, 2012 Central Bankcorp, Inc. [Member]	Dec. 31, 2011 Central Bankcorp, Inc. [Member]	Dec. 31, 2013 Central Bankcorp, Inc. [Member]	Nov. 09, 2012 Central Bankcorp, Inc. [Member]
Business Acquisition [Line Items]
Contractually required principal and interest payments receivable		$ 4,440		$ 47,548	[1]				$ 4,440				$ 47,548
Net interest income after provision for loan losses							178,556	162,781		165,860	170,514
Net income							55,103	44,133		47,261	46,477
Certain Loans Acquired in Transfer, Nonaccretable Difference		(1,296)		(8,733)					(1,296)				(8,733)
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition		3,144		38,815	[1]				3,144				38,815
Interest component of expected cash flows	(2,514)	(386)	(2,464)	(3,095)		0			(386)				(3,095)
Less: fair value (initial carrying amount)		$ 2,758		$ 35,720			$ 2,747		$ 2,758	$ 32,054		$ 26,797	$ 35,720

[1] Reflective of anticipated prepayments.