INCOME TAXES: (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal:
Currently payable	$ 7,118	$ 7,018	$ 8,303
Deferred	2,435	1,793	3,756
Federal tax reform	0	0
Federal income tax expense (benefit), continuing operations	9,553	8,811	18,341
State:
Currently payable	2,168	1,699	1,818
Deferred	406	635	463
State and local income tax expense (benefit), continuing operations	2,574	2,334	2,281
TOTAL	$ 12,127	$ 11,145	$ 20,622