SHORT-TERM BORROWINGS: (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	$ 32,981	$ 26,823
Average amount outstanding	32,617	45,697
Maximum amount outstanding at a month end	$ 84,819	$ 96,452
Average interest rate during year (percent)	0.21%	0.22%
Interest rate at year-end (percent)	0.23%	0.20%
Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	$ 718	$ 618
Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	10,794	5,670
Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	11,049	5,749
Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	$ 10,420	$ 14,786