GOODWILL AND INTANGIBLE ASSETS: (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 21,857	$ 21,205
Accumulated Amortization	13,833	12,233
Core deposit intangible
Finite-Lived Intangible Assets [Line Items]
Gross Amount	21,205	21,205
Accumulated Amortization	$ 13,849	$ 12,233