Retirement Plans, Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost, Pension Benefits (Details)		12 Months Ended
		Dec. 31, 2022		Dec. 31, 2021	Dec. 31, 2020
Pension Benefits [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate		3.00%		2.80%
Expected long-term rate of return on plan assets		6.75%		6.75%	6.75%
Pension Benefits [Member] | Maximum [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate		3.10%	[1]	2.90%	3.10%
Pension Benefits [Member] | Minimum [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate		3.00%	[1]	2.80%	3.50%
Pension Benefits [Member] | Higman [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate		3.10%		2.90%
SERP [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate	[1]	3.00%		2.80%	3.50%
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 2022 discount rate for benefit cost is 3.0% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan. The 2021 discount rate for benefit cost is 2.8% for the Kirby Pension Plan and 2.9% for the Higman Pension Plan.