Retirement Plans, Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost, Pension Benefits (Details)		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023		Dec. 31, 2022
Pension Benefits [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate		5.10%	5.50%	[1]
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	[1]	5.20%			3.10%
Pension Benefits [Member] | Minimum [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate	[1]	5.10%			3.00%
SERP [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate	[1]	5.10%	5.50%		3.00%
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%
Higman Pension Plan [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate		5.20%	5.50%

[1] The 2024 discount rate for benefit cost is 5.1% for the Kirby Pension Plan and 5.2% for the Higman Pension Plan. The 2023 discount rate for benefit cost is 5.5% for both the Kirby Pension Plan and the Higman Pension Plan.