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Retirement Plans, Information About Plan Assets and Asset Allocation (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Information about Plan Assets [Abstract] |  |  |  |  |
Service period of participants not impacted by pension plan amendment |  | 15 years |  |  |
Age of plan participants not impacted by pension plan amendment |  | 50 years |  |  |
Service period of participants who are age fifty not impacted by pension plan amendment |  | 10 years |  |  |
Level 3 [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Fair value of plan assets |  | $ 0 |  | $ 0 |
Cash and Equity Securities [Member] | Level 1 [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Fair value of plan assets |  | 4,800 |  | 5,400 |
Higman [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Pension contributions |  | 900 |  | 500 | $ 2,200
Pension Plan [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Pension contributions |  | 906 |  | 479 |
Fair value of plan assets |  | $ 341,061 |  | $ 430,821 | $ 395,137
Expected long-term rate of return on plan assets |  | 6.75% |  | 6.75% | 6.75%
Contribution percentage to defined contribution plan |  | 105.00% |  |  |
Discount rate |  | 3.00% |  | 2.80% |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Asset allocations |  | 100.00% |  | 100.00% |
Pension Plan [Member] | Minimum [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Discount rate |  | 3.00% | [1] | 2.80% | 3.50%
Pension Plan [Member] | Maximum [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Discount rate |  | 3.10% | [1] | 2.90% | 3.10%
Pension Plan [Member] | Higman [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Discount rate |  | 3.10% |  | 2.90% |
Pension Plan [Member] | U.S. Equity Securities [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Asset allocations |  | 50.00% |  | 51.00% |
Target allocations |  | 50.00% |  |  |
Pension Plan [Member] | U.S. Equity Securities [Member] | Minimum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 45.00% |  |  |
Pension Plan [Member] | U.S. Equity Securities [Member] | Maximum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 55.00% |  |  |
Pension Plan [Member] | International Equity Securities [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Asset allocations |  | 20.00% |  | 20.00% |
Target allocations |  | 20.00% |  |  |
Pension Plan [Member] | International Equity Securities [Member] | Minimum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 12.00% |  |  |
Pension Plan [Member] | International Equity Securities [Member] | Maximum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 28.00% |  |  |
Pension Plan [Member] | Debt Securities [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Asset allocations |  | 30.00% |  | 29.00% |
Target allocations |  | 30.00% |  |  |
Pension Plan [Member] | Debt Securities [Member] | Minimum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 20.00% |  |  |
Pension Plan [Member] | Debt Securities [Member] | Maximum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 40.00% |  |  |
Pension Plan [Member] | Cash and Cash Equivalents [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Asset allocations |  | 0.00% |  | 0.00% |
Target allocations |  | 0.00% |  |  |
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Minimum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 0.00% |  |  |
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Maximum [Member] |  |  |  |  |
Asset Allocation Among Asset Categories [Abstract] |  |  |  |  |
Target allocations |  | 0.00% |  |  |
SERP [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Pension contributions |  | $ 155 |  | $ 160 |
Fair value of plan assets |  | $ 0 |  | $ 0 | $ 0
Expected long-term rate of return on plan assets |  | 0.00% |  | 0.00% | 0.00%
Discount rate | [1] | 3.00% |  | 2.80% | 3.50%
Other Postretirement Benefits [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Pension contributions |  | $ 109 |  | $ 168 |
Fair value of plan assets |  | $ 0 |  | $ 0 | $ 0
Pension plan defined benefit plan cost increase limit percentage |  | 4.00% |  |  |
Discount rate |  | 3.00% |  | 2.80% | 3.50%
Seafarers Pension Trust [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Pension contributions |  | $ 500 |  | $ 500 |
Contribution percentage to defined contribution plan |  |  |  | 100.00% |
Central Pension Fund of the International Union of Operating [Member] |  |  |  |  |
Information about Plan Assets [Abstract] |  |  |  |  |
Pension contributions |  | $ 700 |  | $ 700 |
Contribution percentage to defined contribution plan |  |  |  | 103.00% |
[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.

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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
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