Employee Benefit Plans (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) plan employee	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | plan	4
Target allocation, rebalancing range	5.00%
Assumed annual increases in Medicare Part B trends after eight years	4.50%	4.50%
Anticipated required contributions	$ 88
401 (k) plan cost recognized	$ 1,756	$ 1,590	$ 1,473
Minimum
Defined Benefit Plan Disclosure [Line Items]
Assumed annual increases in Medicare Part B trends for next eight years	5.54%	3.06%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Assumed annual increases in Medicare Part B trends for next eight years	7.23%	8.01%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	35.00%
Investment grade fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	65.00%
Hourly Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Period for amortization of benefit plan gains and losses	12 years 7 months 20 days
Salaried Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Period for amortization of benefit plan gains and losses	11 years 3 days
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | plan	4
2024	$ 5,524
2025	5,177
2026	4,860
2027	4,539
2028	72,548
2029 - 2033	$ 23,577
Ten-year rate of return	4.42%	4.83%	7.74%
Five-year rate of return	3.00%	2.42%	7.86%
Pension Benefits | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | plan	2
Pension Benefits | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | plan	2
Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Age requirement for participant	60 years
Required employment period	8 years
2028	$ 68,316
2029 - 2033	6,866
Supplemental Employee Retirement Plan | President and Chief Executive Officer
Defined Benefit Plan Disclosure [Line Items]
Additional benefit	$ 1,788
Service period credit upon termination	36 months
Postretirement Medical
Defined Benefit Plan Disclosure [Line Items]
2024	$ 601
2025	590
2026	579
2027	551
2028	533
2029 - 2033	$ 2,313
Employee contribution percentage	100.00%
Number of retired employees | employee	43
Postretirement Life Insurance
Defined Benefit Plan Disclosure [Line Items]
Number of retired employees | employee	326
Number of active employees | employee	66