Financial Instruments (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Company owned life insurance policies	[1]	$ 31,326	$ 30,985
Deferred compensation plan, assets		31,326	30,985
Deferred compensation liabilities		23,829	22,559
Deferred compensation plan, liability		$ 29,229	25,050
Interest Rate Swap No. 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of interest rate derivatives			$ 368
Derivative, term of contract		5 years	5 years
Interest Rate Swap No. 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of interest rate derivatives			$ 2,123
Derivative, term of contract		10 years	10 years
Forward Interest Rate Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of interest rate derivatives		$ 5,400
Derivative, term of contract		10 years	10 years
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Company owned life insurance policies	[1]	$ 31,326	$ 30,985
Deferred compensation plan, assets		31,326	30,985
Deferred compensation liabilities		23,829	22,559
Deferred compensation plan, liability		29,229	25,050
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap No. 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of interest rate derivatives			$ 368
Derivative, term of contract			5 years
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap No. 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of interest rate derivatives			$ 2,123
Derivative, term of contract			10 years
Fair Value, Inputs, Level 2 [Member] | Forward Interest Rate Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of interest rate derivatives		$ 5,400
Derivative, term of contract		10 years

[1] Company owned life insurance policies are intended to assist in the funding of the deferred compensation liabilities.