LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES - Summary of loan portfolio (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ (9,552)		$ (8,382)
Loans receivable, net	730,148		621,830
Loans receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	742,084		632,012
Allowance for loan losses	(9,552)	(8,985)	(8,382)	(8,277)	(8,224)	(7,941)
Deferred loan origination fees, net	(2,400)		(1,816)
Unamortized loan premiums	16		16
Loans receivable, net	730,148		621,830
Loans receivable | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	167,362		155,874
Allowance for loan losses	(1,411)	(1,392)	(1,310)	(1,469)	(1,326)	(1,230)
Loans receivable | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	400,915		315,762
Allowance for loan losses	(4,661)	(4,024)	(3,616)	(3,591)	(3,672)	(3,842)
Loans receivable | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	53,280		51,495
Allowance for loan losses	(891)	(776)	(1,032)	(928)	(1,013)	(929)
Loans receivable | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	12,833		13,497
Allowance for loan losses	(191)	(188)	(190)	(212)	(213)	(220)
Loans receivable | Real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	634,390		536,628
Loans receivable | Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	107,161		94,547
Allowance for loan losses	(2,391)	(2,292)	(2,225)	(2,052)	(1,766)	(1,718)
Loans receivable | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	533		837
Allowance for loan losses	(7)	(6)	(9)	(10)	(91)	(2)
Loans receivable | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	728,605		607,907
Allowance for loan losses	(9,552)	(8,984)	(8,382)
Deferred loan origination fees, net	(2,400)		(1,785)
Unamortized loan premiums	16		16
Loans receivable, net	716,669		597,756
Loans receivable | Originated | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	167,362		155,874
Allowance for loan losses	(1,411)	(1,392)	(1,310)
Loans receivable | Originated | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	394,004		305,823
Allowance for loan losses	(4,661)	(4,024)	(3,616)
Loans receivable | Originated | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	52,387		44,187
Allowance for loan losses	(891)	(776)	(1,032)
Loans receivable | Originated | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	9,539		9,625
Allowance for loan losses	(191)	(188)	(190)
Loans receivable | Originated | Real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	623,292		515,509
Loans receivable | Originated | Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	105,123		92,173
Allowance for loan losses	(2,391)	(2,291)	(2,225)
Loans receivable | Originated | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	190		225
Allowance for loan losses	(7)	(6)	(9)
Loans receivable | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	13,479		24,105
Allowance for loan losses		(1)
Deferred loan origination fees, net			(31)
Unamortized loan premiums
Loans receivable, net	13,479		24,074
Loans receivable | Acquired | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans
Allowance for loan losses
Loans receivable | Acquired | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	6,911		9,939
Allowance for loan losses
Loans receivable | Acquired | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	893		7,308
Allowance for loan losses
Loans receivable | Acquired | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,294		3,872
Allowance for loan losses
Loans receivable | Acquired | Real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	11,098		21,119
Loans receivable | Acquired | Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,038		2,374
Allowance for loan losses		(1)
Loans receivable | Acquired | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	343		612
Allowance for loan losses