FINANCIAL INSTRUMENTS WITH OFF-BALANCE-SHEET RISK: (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Other Commitments			$ 66,408,000	$ 53,026,000
TOTAL			390,347,000	364,756,000
Minimum
Loss Contingencies [Line Items]
Loans and Leases Receivable, Commitments, Fixed Rates	$ 0.0325	$ 0.0325
Maximum
Loss Contingencies [Line Items]
Loans and Leases Receivable, Commitments, Fixed Rates	$ 0.0700	$ 0.0650
Commercial Operating Lines
Loss Contingencies [Line Items]
TOTAL			268,577,000	259,019,000
Commercial letters of credit
Loss Contingencies [Line Items]
TOTAL			5,673,000	7,195,000
Home Equity
Loss Contingencies [Line Items]
TOTAL			$ 55,362,000	$ 52,711,000