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Retirement Plans, Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost, Pension Benefits (Details)
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Pension Benefits [Member]      
Weighted average assumptions used to determine net periodic benefit cost [Abstract]      
Discount rate 2.80% 3.50% 4.40% [1]
Expected long-term rate of return on plan assets 6.75% 6.75% 7.00%
Pension Benefits [Member] | Maximum [Member]      
Weighted average assumptions used to determine net periodic benefit cost [Abstract]      
Discount rate 2.90% 3.50%  
Pension Benefits [Member] | Minimum [Member]      
Weighted average assumptions used to determine net periodic benefit cost [Abstract]      
Discount rate 2.80% 3.10%  
Pension Benefits [Member] | Higman [Member]      
Weighted average assumptions used to determine net periodic benefit cost [Abstract]      
Discount rate 2.90% 3.10%  
SERP [Member]      
Weighted average assumptions used to determine net periodic benefit cost [Abstract]      
Discount rate [1] 2.80% 3.50% 4.40%
Expected long-term rate of return on plan assets 0.00% 0.00% 0.00%
Rate of compensation increase 0.00% 0.00% 0.00%
[1] The 2021 discount rate for benefit cost is 2.8% for the Kirby Pension Plan and 2.9% for the Higman Pension Plan. The 2020 discount rate for benefit cost is 3.5% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan.