RETIREMENT PLANS: (Details 5) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 87,979	$ 82,437	$ 73,962
Quoted Prices in Active Markets for Identical Assets - Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	77,877	69,764
Significant Other Observable Inputs - Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,102	12,673
Significant Observable Inputs - Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	62,382	55,235
Equity Securities | Quoted Prices in Active Markets for Identical Assets - Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	62,382	55,235
Equity Securities | Significant Other Observable Inputs - Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Securities | Significant Observable Inputs - Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,102	12,673
Debt securities | Quoted Prices in Active Markets for Identical Assets - Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt securities | Significant Other Observable Inputs - Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,102	12,673
Debt securities | Significant Observable Inputs - Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,495	14,529
Investment Funds | Quoted Prices in Active Markets for Identical Assets - Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,495	14,529
Investment Funds | Significant Other Observable Inputs - Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment Funds | Significant Observable Inputs - Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0