SHORT-TERM BORROWINGS: (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	$ 90,099	$ 109,561
Average amount outstanding	99,810	90,561
Maximum amount outstanding at a month end	$ 117,337	$ 116,061
Average interest rate during year (percent)	0.40%	0.63%
Interest rate at year-end (percent)	0.08%	0.11%
Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	$ 707	$ 798
Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	5,816	21,342
Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	0	1,086
Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase-agreements	$ 83,576	$ 86,335