GOODWILL AND INTANGIBLE ASSETS: (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 10,836	$ 15,607
Accumulated Amortization	8,727	12,429
Customer list intangible
Finite-Lived Intangible Assets [Line Items]
Gross Amount	0	4,771
Accumulated Amortization	0	4,309
Core deposit intangible
Finite-Lived Intangible Assets [Line Items]
Gross Amount	10,836	10,836
Accumulated Amortization	$ 8,727	$ 8,120