RETIREMENT PLANS: (Details 9) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in benefit obligation:
Benefit obligation at January 1	$ 109,922	$ 102,791
Service cost	1,355	1,300	$ 1,218
Interest cost	2,632	3,116	3,465
Actuarial (gain) loss	(2,943)	6,845
Defined Benefit Plan, Benefit Obligation, Benefits Paid	4,470	4,130
Benefit obligation at December 31	106,496	109,922	102,791
Funded status at December 31	(18,517)	(27,485)
Supplemental Employee Retirement Plans, Defined Benefit
Change in benefit obligation:
Benefit obligation at January 1	4,147	3,975
Service cost	43	38
Interest cost	103	125
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	34	75
Actuarial (gain) loss	(53)	238
Defined Benefit Plan, Benefit Obligation, Benefits Paid	259	304
Benefit obligation at December 31	4,015	4,147	$ 3,975
Funded status at December 31	$ 4,015	$ 4,147