10-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

(Mark One)

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2023

or

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File no. 1-07615

Kirby Corporation

(Exact name of registrant as specified in its charter)

Nevada	74-1884980
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
55 Waugh Drive, Suite 1000
Houston, Texas	77007
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code:

713-435-1000

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock	KEX	New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Exchange Act. Yes ☐ No ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer	☒	Accelerated filer	☐
Non-accelerated filer	☐	Smaller reporting company	☐
		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒

The aggregate market value of common stock held by non-affiliates of the registrant as of June 30, 2023, based on the closing sales price of such stock on the New York Stock Exchange on June 30, 2023, was $4.5 billion. For purposes of this computation, all executive officers, directors and 10% beneficial owners of the registrant are deemed to be affiliates. Such determination should not be deemed an admission that such executive officers, directors and 10% beneficial owners are affiliates.

As of February 16, 2024, 58,522,000 shares of common stock were outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the Company’s definitive proxy statement in connection with the Annual Meeting of Stockholders to be held April 26, 2024, to be filed with the Commission pursuant to Regulation 14A, and the related annual report for the fiscal year ended December 31, 2023, to be provided to the Company's stockholders pursuant to Rule 14a-3(b) are incorporated by reference into Parts II and III of this report.

KIRBY CORPORATION
2023 FORM 10-K
TABLE OF CONTENTS

		Page
PART I
	Item 1. Business	4
	THE COMPANY	4
	Documents and Information Available on Website	4
	BUSINESS AND PROPERTY	4
	MARINE TRANSPORTATION	5
	Marine Transportation Industry Fundamentals	6
	Inland Tank Barge Industry	6
	Coastal Tank Barge Industry	7
	Competition in the Tank Barge Industry	7
	Products Transported	8
	Demand Drivers in the Tank Barge Industry	8
	Marine Transportation Operations	9
	Contracts and Customers	11
	DISTRIBUTION AND SERVICES	12
	Commercial and Industrial Operations	12
	Commercial and Industrial Customers	13
	Commercial and Industrial Competitive Conditions	14
	Oil and Gas Operations	14
	Oil and Gas Customers	14
	Oil and Gas Competitive Conditions	14
	Governmental Regulations	15
	Environmental Regulations	16
	Human Capital	18
	Information about the Company’s Executive Officers	19
	Item 1A. Risk Factors	21
	Item 1B. Unresolved Staff Comments	28
	Item 1C. Cybersecurity	28
	Item 2. Properties	30
	Item 3. Legal Proceedings	31
	Item 4. Mine Safety Disclosures	31
PART II
	Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities	32
	Item 6. Reserved	32
	Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations	33
	Item 7A. Quantitative and Qualitative Disclosures about Market Risk	47
	Item 8. Financial Statements and Supplementary Data	47
	Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure	47
	Item 9A. Controls and Procedures	48
	Item 9B. Other Information	48
	Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections	48
PART III
	Items 10 Through 14	48
PART IV
	Item 15. Exhibits and Financial Statement Schedules	78
	Item 16. Form 10-K Summary	79

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PART I

Item 1. Business

THE COMPANY

Kirby Corporation (the “Company”) is the nation’s largest domestic tank barge operator, transporting bulk liquid products throughout the Mississippi River System, on the Gulf Intracoastal Waterway, and coastwise along all three United States coasts. The Company, through its marine transportation segment (“KMT”), transports petrochemicals, black oil, refined petroleum products, and agricultural chemicals by tank barge. Through its distribution and services segment (“KDS”), the Company sells after-market service and genuine replacement parts for engines, transmissions, reduction gears, and power generation equipment used in oil and gas and commercial and industrial applications. The Company also rents a variety of power generation and industrial equipment, manufactures and remanufactures oilfield service equipment, including pressure pumping units, and manufactures electric power generation equipment for oilfield service customers.

Unless the context otherwise requires, all references herein to the Company include the Company and its subsidiaries. The Company’s principal executive office is located at 55 Waugh Drive, Suite 1000, Houston, Texas 77007, and its telephone number is 713-435-1000. The Company’s mailing address is P.O. Box 1745, Houston, Texas 77251-1745. Kirby Corporation is a Nevada corporation and was incorporated in 1969 although the history of the Company goes back to 1921.

Documents and Information Available on Website

The Internet address of the Company’s website is http://www.kirbycorp.com. The Company makes available free of charge through its website, all of its filings with the Securities and Exchange Commission (“SEC”), including its Annual Report on Form 10‑K, Quarterly Reports on Form 10‑Q, Current Reports on Form 8‑K and amendments to those reports, as soon as reasonably practicable after they are electronically filed with or furnished to the SEC. The SEC maintains an internet site at http://www.sec.gov that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC.

The following documents are available on the Company’s website in the Investor Relations section under Governance Documents:

•	Audit Committee Charter	•	Corporate Governance Guidelines
•	Compensation Committee Charter	•	Clawback Policy
•	ESG and Nominating Committee Charter	•	Insider Trading Policy
•	Business Ethics Guidelines

The Company is required to make prompt disclosure of any amendment to or waiver of any provision of its Business Ethics Guidelines that applies to any director or executive officer or to its chief executive officer, chief financial officer, chief accounting officer or controller or persons performing similar functions. The Company will make any such disclosure that may be necessary by posting the disclosure on its website in the Investor Relations section under Corporate Governance.

BUSINESS AND PROPERTY

The Company, through its subsidiaries, conducts operations in two reportable business segments: marine transportation and distribution and services.

The Company, through KMT, is a provider of marine transportation services, operating tank barges and towing vessels transporting bulk liquid products throughout the Mississippi River System, on the Gulf Intracoastal Waterway, and coastwise along all three United States coasts. The Company transports petrochemicals, black oil, refined petroleum products, and agricultural chemicals by tank barge. The Company operates offshore dry-bulk barge and tugboat units engaged in the offshore transportation of dry-bulk cargoes in the United States coastal trade. The segment is a provider of transportation services for its customers and, in almost all cases, does not assume ownership of the products that it transports. All of the Company’s vessels operate under the United States flag and are qualified for domestic trade under the Jones Act.

The Company, through KDS, sells after-market services and genuine replacement parts for engines, transmissions, reduction gears, electric motors, drives, and controls, specialized electrical distribution and control systems, energy storage battery systems, and related oilfield services equipment, rebuilds component parts or entire diesel engines, transmissions and reduction gears, and related equipment used in oilfield services, marine, power generation, on-highway and other industrial applications. The Company also rents equipment including generators, industrial compressors, high capacity lift trucks, and refrigeration trailers for use in a variety of industrial markets, and manufactures and remanufactures oilfield service equipment, including pressure pumping units, and manufacturers cementing and pumping equipment as well as coil tubing and well intervention equipment, electric power generation equipment, specialized electrical distribution and control equipment, and high capacity energy storage/battery systems for oilfield service and railroad customers.

The Company has approximately 5,450 employees, the large majority of whom are in the United States.

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MARINE TRANSPORTATION

KMT is primarily a provider of transportation services by tank barge for the inland and coastal markets. As of December 31, 2023, the equipment owned or operated by KMT consisted of 1,076 inland tank barges with 23.7 million barrels of capacity, and an average of 281 inland towboats during the fourth quarter of 2023, as well as 28 coastal tank barges with 2.9 million barrels of capacity, 25 coastal tugboats, four offshore dry-bulk cargo barges, four offshore tugboats and one docking tugboat with the following specifications and capacities:

Class of equipment	Number in class		Average age (in years)		Barrel capacities
Inland tank barges (owned and leased):
Regular double hull:
20,000 barrels and under		384		15.9		4,499,000
Over 20,000 barrels		637		14.6		18,301,000
Specialty double hull		55		37.6		924,000
Total inland tank barges		1,076		16.2		23,724,000
Inland towboats (owned and chartered):
800 to 1300 horsepower		29		34.7
1400 to 1900 horsepower		31		25.0
2000 to 2400 horsepower		165		12.8
2500 to 3200 horsepower		42		10.9
3300 to 4800 horsepower		9		23.4
Greater than 5000 horsepower		5		24.1
Total inland towboats		281		16.7
Coastal tank barges (owned):
30,000 barrels and under		2		29.0		37,000
50,000 to 70,000 barrels		3		18.3		111,000
80,000 to 90,000 barrels		8		19.9		677,000
100,000 to 110,000 barrels		6		17.5		630,000
120,000 to 150,000 barrels		3		22.0		416,000
Over 150,000 barrels		6		8.1		1,046,000
Total coastal tank barges		28		17.6		2,917,000
Coastal tugboats (owned and chartered):
2000 to 2900 horsepower		1		48.1
3000 to 3900 horsepower		1		21.0
4000 to 4900 horsepower		7		19.0
5000 to 6900 horsepower		10		7.8
Greater than 7000 horsepower		6		13.5
Total coastal tugboats		25		14.4
					Deadweight Tonnage
Offshore dry-bulk cargo barges (owned)		4		25.1		67,000
Offshore tugboats and docking tugboat (owned and chartered)		5		32.5

The 281 inland towboats, 25 coastal tugboats, four offshore tugboats and one docking tugboat provide the power source and the 1,076 inland tank barges, 28 coastal tank barges and four offshore dry-bulk cargo barges provide the freight capacity for KMT. When the power source and freight capacity are combined, the unit is called a tow. The Company’s inland tows generally consist of one towboat and from one to up to 25 tank barges, depending upon the horsepower of the towboat, the waterway infrastructure capacity and conditions, and customer requirements. The Company’s coastal and offshore tows primarily consist of one tugboat and one tank barge or dry-bulk cargo barge.

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Marine Transportation Industry Fundamentals

The United States inland waterway system, composed of a network of interconnected rivers and canals that serve the nation as water highways, is one of the world’s most efficient transportation systems. The nation’s inland waterways are vital to the United States distribution system, with over one billion short tons of cargo moved annually on United States shallow draft waterways. The inland waterway system extends approximately 26,000 miles, 12,000 miles of which are generally considered significant for domestic commerce, through 38 states, with 635 shallow draft ports. These navigable inland waterways link the United States heartland to the world.

The United States coastal waterway system consists of ports along the Atlantic, Gulf and Pacific coasts, as well as ports in Alaska, Hawaii and on the Great Lakes. Like the inland waterways, the coastal trade is vital to the United States distribution system, particularly the regional distribution of refined petroleum products from refineries and storage facilities to a variety of destinations, including other refineries, distribution terminals, power plants and ships. In addition to distribution directly from refineries and storage facilities, coastal tank barges are used frequently to distribute products from pipelines. Many coastal markets receive refined petroleum products principally from coastal tank barges. Smaller volumes of petrochemicals are distributed from Gulf Coast plants to end users whereas black oil, including crude oil and natural gas condensate, is distributed regionally from refineries and terminals along the United States coast to refineries, power plants and distribution terminals.

Based on cost, safety, and level of emissions, barge transportation is often the most efficient and safest means of surface transportation of bulk commodities when compared to railroads and trucks. The cargo capacity of a 27,500 barrel inland tank barge is the equivalent of 46 railroad tank cars or 144 tractor-trailer tank trucks. A typical Company lower Mississippi River linehaul tow of 15 barges has the carrying capacity of approximately 216 railroad tank cars plus six locomotives, or approximately 1,050 tractor-trailer tank trucks. The Company’s inland tank barge fleet capacity of 23.7 million barrels equates to approximately 39,700 railroad tank cars or approximately 124,000 tractor-trailer tank trucks. Furthermore, barging is much more energy efficient. One ton of bulk product can be carried 675 miles by inland barge on one gallon of fuel on a typical tow, compared to 472 miles by railcar or 151 miles by truck for typical transits. From an emissions perspective, transport by rail and tractor-trailer tank trucks emit approximately 40% and 800%, respectively, more CO2 per ton mile of cargo transported than by inland tank barge. In the coastal trade, the carrying capacity of a 100,000 barrel tank barge is the equivalent of approximately 165 railroad tank cars or approximately 525 tractor-trailer tank trucks. The Company’s coastal tank barge fleet capacity of 2.9 million barrels equates to approximately 4,800 railroad tank cars or approximately 15,300 tractor-trailer tank trucks. Marine transportation generally involves less urban exposure than railroad or truck transportation and operates on a system with few crossing junctures and often in areas relatively remote from population centers. These factors generally help to reduce the number of waterway incidents.

Inland Tank Barge Industry

The Company operates within the United States inland tank barge industry, a diverse and independent mixture of approximately 25 large integrated transportation companies and small operators, as well as captive fleets owned by refining and petrochemical companies. The inland tank barge industry provides marine transportation of bulk liquid cargoes for customers and, in the case of captives, for their own account, throughout the Mississippi River and its tributaries and on the Gulf Intracoastal Waterway. The most significant markets in this industry include the transportation of petrochemicals, black oil, refined petroleum products, and agricultural chemicals. The Company operates in each of these markets. The use of marine transportation by the petroleum and petrochemical industry is a major reason for the location of United States refineries and petrochemical facilities on navigable inland waterways. Texas and Louisiana currently account for approximately 80% of the United States production of petrochemicals. Much of the United States farm belt is likewise situated with access to the inland waterway system, relying on marine transportation of farm products, including agricultural chemicals. The Company’s principal distribution system encompasses the Gulf Intracoastal Waterway from Brownsville, Texas, to Port St. Joe, Florida, the Mississippi River System and the Houston Ship Channel. The Mississippi River System includes the Arkansas, Illinois, Missouri, Ohio, Red, Tennessee, Yazoo, Ouachita and Black Warrior Rivers and the Tennessee-Tombigbee Waterway.

The number of tank barges that operate on the inland waterways of the United States increased from 2,750 in 2006 to approximately 4,000 by the end of 2019. The increase from 2,750 tank barges in 2006 to approximately 4,000 by the end of 2019 primarily resulted from increased barge construction and deferred retirements due to strong demand and resulting capacity shortages. The number of industry tank barges has remained relatively constant from 2019 through the end of 2023. The Company’s 1,076 inland tank barges represent approximately 27% of the industry’s approximately 4,007 inland tank barges.

For 2022, the Company estimates that industry-wide, 22 new tank barges were placed in service and retirements, net of reactivations, were flat. For 2023, the Company estimates that industry-wide 27 new tank barges were placed in service and 48 tank barges were retired. During 2021, the Company’s inland barge utilization improved to the mid-to high 80% range by the fourth quarter as the economy began to recover from the COVID-19 pandemic. During 2022, the Company’s inland barge utilization improved to the low 90% range reflecting increased activity levels as a result of higher refinery and petrochemical plant utilization. During 2023, the Company’s inland barge utilization remained in the low 90% range as improved activity levels were offset by lock closures and several

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refinery outages. The Company estimates that approximately 25 to 30 new tank barges have currently been ordered for delivery in 2024. Generally, the risk of an oversupply of tank barges may be mitigated by increased petrochemical, black oil and refined petroleum products volumes from increased production from current facilities, plant expansions, the opening of new facilities, and the fact that the inland tank barge industry has approximately 600 tank barges that are 30 years old or older and approximately 400 of those are 40 years old or older, which could lead to retirement of these older tank barges. The average age of the nation’s inland tank barge fleet is approximately 18 years.

The Company’s inland division of KMT also owns a shifting operation and fleeting facility for dry cargo barges and tank barges on the Houston Ship Channel, in Freeport and Port Arthur, Texas, and Lake Charles, Louisiana, and a shipyard for building inland towboats and providing routine maintenance on marine vessels. The Company also owns a two-thirds interest in Osprey Line, L.L.C. (“Osprey”), a transporter of project cargoes and cargo containers by barge on the United States inland waterway system.

Coastal Tank Barge Industry

The Company also operates in the United States coastal tank barge industry, operating tank barges in the 195,000 barrels or less category. This market is composed of approximately 20 large integrated transportation companies and small operators. The 195,000 barrels or less category coastal tank barge industry primarily provides regional marine transportation distribution of bulk liquid cargoes along the United States’ Atlantic, Gulf and Pacific coasts, in Alaska and Hawaii, and to a lesser extent, on the Great Lakes. Products transported are primarily refined petroleum products and black oil from refineries and storage facilities to a variety of destinations, including other refineries, distribution terminals, power plants and ships, the regional movement of crude oil and natural gas condensate to Gulf Coast, Northeast and West Coast refineries, and the movement of petrochemicals primarily from Gulf Coast petrochemical facilities to end users.

The number of coastal tank barges that operate in the 195,000 barrels or less category is approximately 264, of which the Company operates 28 or approximately 11%. The average age of the nation’s coastal tank barge fleet is approximately 15 years. The Company is aware of no specialized coastal articulated tank barge and tugboat units (“ATB”) that were delivered in 2023 with no further ATBs currently under construction. The coastal tank barge fleet has approximately 20 tank barges that are over 25 years old industry-wide. The number of older tank barges, coupled with ballast water treatment regulations, could lead to further retirements of these older tank barges in the next few years.

Competition in the Tank Barge Industry

The tank barge industry is very competitive. Competition in this business is based on price and reliability, with many of the industry’s customers emphasizing enhanced vetting requirements, an increased emphasis on safety, the environment, and high-quality service consistent with the customer’s operational standards. Customers also require that their supplier of tank barge services have the ability to handle a variety of requirements, including distribution capabilities throughout the inland waterway system and coastal markets, high levels of flexibility, and an emphasis on safety, environmental and financial responsibility, as well as appropriate insurance coverage.

In the inland markets, the Company’s direct competitors are primarily noncaptive inland tank barge operators. “Captive” fleets are owned by refining and petrochemical companies which occasionally compete in the inland tank barge market, but primarily transport cargoes for their own account. The Company is the largest inland tank barge carrier, both in terms of number of barges and total fleet barrel capacity. The Company’s inland tank barge fleet has grown from 71 tank barges in 1988 to 1,076 tank barges as of December 31, 2023, or approximately 27% of the estimated total number of domestic inland tank barges.

In the coastal markets, the Company’s direct competitors are the operators of United States tank barges in the 195,000 barrels or less category. Coastal tank barges in the 195,000 barrels or less category have the ability to enter the majority of coastal ports. Ocean-going tank barges and United States product tankers in the 300,000 barrels plus category, excluding the fleet of large tankers dedicated to Alaska crude oil transportation, occasionally compete in the 195,000 barrels or less market to move large volumes of refined petroleum products within the Gulf of Mexico with occasional movements from the Gulf Coast to the East Coast, along the West Coast and from Texas and Louisiana to Florida. However, access to United States ports of approximately 45 such product tankers is limited by terminal size and draft restrictions.

While the Company competes primarily with other tank barge companies, it also competes with companies who operate refined product and petrochemical pipelines, railroad tank cars, and tractor-trailer tank trucks. As noted above, the Company believes that both inland and coastal marine transportation of bulk liquid products enjoy a substantial cost advantage over railroad and truck transportation on a barrel per mile basis. The Company believes that refined product and crude oil pipelines, although often a less expensive form of transportation than inland and coastal tank barges, are not as adaptable to diverse products and are generally limited to fixed point-to-point distribution of commodities in high volumes over extended periods of time.

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Products Transported

The Company transports petrochemicals, black oil, refined petroleum products, and agricultural chemicals by tank barge throughout the Mississippi River System, on the Gulf Intracoastal Waterway, and coastwise along all three United States coasts. During 2023, the Company’s inland marine transportation operation moved over 56 million tons of liquid cargo on the United States inland waterway system.

Petrochemicals. Bulk liquid petrochemicals transported include such products as benzene, styrene, methanol, acrylonitrile, xylene, naphtha and caustic soda. These products are consumed in the production of paper, fiber and plastics. Pressurized products, including butadiene, isobutane, propylene, butane and propane, all requiring pressurized conditions to remain in stable liquid form, are transported in pressure barges. The transportation of petrochemical products represented 51% of the segment’s 2023 revenues. Customers shipping these products are petrochemical and refining companies.

Black Oil. Black oil transported includes such products as residual fuel oil, No. 6 fuel oil, coker feedstock, vacuum gas oil, asphalt, carbon black feedstock, crude oil, natural gas condensate and ship bunkers (engine fuel). Such products represented 26% of the segment’s 2023 revenues. Black oil customers are refining companies, marketers, and end users that require the transportation of black oil between refineries and storage terminals, to other refineries and to power plants. Ship bunker customers are oil companies and oil traders in the bunkering business.

Refined Petroleum Products. Refined petroleum products transported include the various blends of finished gasoline, gasoline blendstocks, jet fuel, No. 2 oil, heating oil and diesel fuel, and represented 20% of the segment’s 2023 revenues. The Company also classifies ethanol in the refined petroleum products category. Customers are oil and refining companies, marketers and ethanol producers.

Agricultural Chemicals. Agricultural chemicals transported represented 3% of the segment’s 2023 revenues. Agricultural chemicals include anhydrous ammonia and nitrogen-based liquid fertilizer, as well as industrial ammonia. Agricultural chemical customers consist mainly of domestic and foreign producers of such products.

Demand Drivers in the Tank Barge Industry

Demand for tank barge transportation services is driven by the production volumes of the bulk liquid commodities. Marine transportation demand for the segment’s four primary commodity groups, petrochemicals, black oil, refined petroleum products and agricultural chemicals, is based on differing circumstances. While the demand drivers of each commodity are different, the Company has the flexibility, in certain cases, of reallocating inland equipment and coastal equipment among the petrochemical, refined petroleum products and black oil markets as needed.

Petrochemical products are used in both consumer non-durable and durable goods. Bulk petrochemical volumes have historically tracked the general domestic economy and correlate to the United States Gross Domestic Product. During 2021, inland barge utilization improved from the mid-70% range during the 2021 first quarter to the mid-to high 80% range in the 2021 fourth quarter as the economy recovered from the impact of COVID-19. During 2022, the Company’s inland barge utilization improved to the high 80% range reflecting increased activity levels as a result of higher refinery and petrochemical plant utilization. During 2023, the Company’s inland barge utilization improved to the low 90% range as improved activity levels were partially offset by lock closures and several refinery outages. Coastal tank barge utilization for the transportation of petrochemicals increased from the low 90% range in 2022 to the mid 90% range during 2023 due to improved economic conditions.

The demand for black oil, including ship bunkers, varies by type of product transported. Demand for transportation of residual oil, a heavy by-product of refining operations, varies with refinery utilization and usage of feedstocks. During 2021 through 2023, the Company continued to transport crude oil and natural gas condensate produced from the Eagle Ford and Permian Basin shale formations in Texas, both along the Gulf Intracoastal Waterway with inland vessels and in the Gulf of Mexico with coastal equipment, and continued to transport Utica crude oil and natural gas condensate downriver from the Mid-Atlantic to the Gulf Coast, albeit, at reduced levels as some of the product was transported by newly constructed pipelines. During 2021, volumes recovered from the lows seen in 2020 as economic activity improved. During 2021, inland black oil tank barge utilization averaged in the mid-70% range during the first nine months of 2021 and recovered to the high 80% range in the 2021 fourth quarter. During 2022, inland black oil tank barge utilization further improved to the high 90% range in the 2022 fourth quarter. During 2023, inland black oil tank barge utilization averaged in the high 90% range. Coastal black oil tank barge utilization averaged in the mid 90% range in 2022 and the high 90% range in 2023 as utilization was supported by a higher percentage of term contracts. Inland and coastal asphalt shipments are generally seasonal, with higher volumes shipped during April through November, months when weather allows for efficient road construction.

Refined petroleum product volumes are driven by United States gasoline and diesel fuel consumption, principally vehicle usage, air travel, and weather conditions. Volumes can also be affected by gasoline inventory imbalances within the United States. Generally, gasoline and No. 2 oil are exported from the Gulf Coast where refining capacity exceeds demand. The Midwest is a net importer of such

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products. Volumes were also driven by diesel fuel transported to terminals along the Gulf Coast for export to South America. Ethanol, produced in the Midwest, is moved from the Midwest to the Gulf Coast. In the coastal trade, tank barges are frequently used regionally to transport refined petroleum products from a coastal refinery or terminals served by pipelines to the end markets. Many coastal areas rely upon access to refined petroleum products by using marine transportation in the distribution chain. In 2022, coastal refined petroleum products tank barge utilization averaged in the low 90% range. During 2023, coastal refined petroleum products tank barge utilization averaged in the high 90% range as activity levels continued to improve.

Demand for marine transportation of domestic and imported agricultural fertilizer is seasonal and directly related to domestic nitrogen-based liquid fertilizer consumption, driven by the production of corn, cotton and wheat. During periods of high natural gas prices, the manufacturing of nitrogen-based liquid fertilizer in the United States is curtailed. During these periods, imported products, which normally involve longer barge trips, replace the domestic products to meet Midwest and South Texas demands. Such products are delivered to the numerous small terminals and distributors throughout the United States farm belt.

Marine Transportation Operations

KMT operated a fleet of 1,076 inland tank barges and an average of 281 inland towboats during the 2023 fourth quarter, as well as 28 coastal tank barges and 25 coastal tugboats. The segment also operated four offshore dry-bulk cargo barges, four offshore tugboats and one docking tugboat transporting dry-bulk commodities in United States coastal trade.

Inland Operations. The segment’s inland operations are conducted through a wholly owned subsidiary, Kirby Inland Marine, LP (“Kirby Inland Marine”). Kirby Inland Marine’s operations consist of the Canal, Linehaul and River fleets, as well as barge fleeting services.

The Canal fleet transports petrochemical feedstocks, processed chemicals, pressurized products, black oil, and refined petroleum products along the Gulf Intracoastal Waterway, the Mississippi River below Baton Rouge, Louisiana, and the Houston Ship Channel. Petrochemical feedstocks and certain pressurized products are transported from one plant to another plant for further processing. Processed chemicals and certain pressurized products are moved to waterfront terminals and chemical plants. Black oil is transported to waterfront terminals and products such as No. 6 fuel oil are transported directly to the end users. Refined petroleum products are transported to waterfront terminals along the Gulf Intracoastal Waterway for distribution.

The Linehaul fleet transports petrochemical feedstocks, chemicals, agricultural chemicals and lube oils along the Gulf Intracoastal Waterway, Mississippi River and the Illinois and Ohio Rivers. Loaded tank barges are staged in the Baton Rouge area from Gulf Coast refineries and petrochemical plants, and are transported from Baton Rouge, Louisiana to waterfront terminals and plants on the Mississippi, Illinois and Ohio Rivers, and along the Gulf Intracoastal Waterway, on regularly scheduled linehaul tows. Tank barges are dropped off and picked up going up and down river.

The River fleet transports petrochemical feedstocks, chemicals, refined petroleum products, agricultural chemicals and black oil along the Mississippi River System above Baton Rouge. The River fleet operates unit tows, where a towboat and generally a dedicated group of barges operate on consecutive voyages between loading and discharge points. Petrochemical feedstocks and processed chemicals are transported to waterfront petrochemical and chemical plants, while black oil, refined petroleum products and agricultural chemicals are transported to waterfront terminals.

The inland transportation of petrochemical feedstocks, chemicals and pressurized products is generally consistent throughout the year. Transportation of refined petroleum products, certain black oil and agricultural chemicals is generally more seasonal. Movements of black oil, such as asphalt, generally increase in the spring through fall months. Movements of refined petroleum products, such as gasoline blends, generally increase during the summer driving season, while heating oil movements generally increase during the winter months. Movements of agricultural chemicals generally increase during the spring and fall planting seasons.

The marine transportation inland operation moves and handles a broad range of sophisticated cargoes. To meet the specific requirements of the cargoes transported, the inland tank barges may be equipped with self-contained heating systems, high-capacity pumps, pressurized tanks, refrigeration units, stainless steel tanks, aluminum tanks or specialty coated tanks. Of the 1,076 inland tank barges currently operated, 826 are petrochemical and refined petroleum products barges, 157 are black oil barges, 83 are pressure barges and 10 are refrigerated anhydrous ammonia barges. Of the 1,076 inland tank barges, 1,043 are owned by the Company and 33 are leased.

The fleet of 281 inland towboats for the 2023 fourth quarter ranges from 800 to 6,100 horsepower. Of the 281 inland towboats, 214 are owned by the Company and 67 are chartered. Towboats in the 800 to 2,100 horsepower classes provide power for barges used by the Canal and Linehaul fleets on the Gulf Intracoastal Waterway and the Houston Ship Channel. Towboats in the 1,400 to 3,200 horsepower classes provide power for both the River and Linehaul fleets on the Gulf Intracoastal Waterway and the Mississippi River System. Towboats above 3,600 horsepower are typically used on the Mississippi River System to move River fleet unit tows and provide Linehaul fleet towing. Based on the capabilities of the individual towboats used in the Mississippi River System, the tows range in size from 10,000 to 30,000 tons.

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Marine transportation services for inland movements are conducted under term contracts, which have contract terms of 12 months or longer, or spot contracts, which have contract terms of less than 12 months, with customers with whom the Company has traditionally had long-standing relationships. Typically, term contracts range from one to three years, some of which have renewal options. During 2021, approximately 65% of inland marine transportation revenues were under term contracts and 35% were under spot contracts. During 2022 and 2023, approximately 60% of inland marine transportation revenues were under term contracts and 40% were under spot contracts.

All of the Company’s inland tank barges used in the transportation of bulk liquid products are of double hull construction and are capable of controlling vapor emissions during loading and discharging operations in compliance with occupational safety and health regulations and air quality regulations.

The Company has the ability to offer its customers optimized distribution capabilities throughout the Mississippi River System and the Gulf Intracoastal Waterway. Such capabilities offer economies of scale from matching tank barges, towboats, products, and destinations efficiently to meet its customers’ requirements.

Through the Company’s proprietary vessel management computer system, the Company’s barge and towboat fleet is dispatched from a centralized dispatch group. The towboats are equipped with cellular and satellite positioning and communication systems that automatically transmit the location of the towboat to the Company’s customer service department. Electronic orders are communicated to vessel personnel with reports of towing activities fed back electronically to the customer service department. The electronic interface between the customer service department and the vessel enables matching of customer needs to barge capabilities, thereby promoting efficient utilization of the tank barge and towboat fleet. The Company’s customers are able to access information concerning the movement of their cargoes, including barge locations, through the Company’s proprietary electronic customer service portal.

Kirby Inland Marine operates the largest commercial tank barge fleeting service (barge storage facilities) in numerous ports, including Houston, Corpus Christi, Freeport and Orange, Texas, Baton Rouge, Lake Charles and New Orleans, Louisiana, Mobile, Alabama, and Greenville, Mississippi. Included in the fleeting service is a shifting operation and fleeting service for dry cargo barges and tank barges on the Houston Ship Channel, in Freeport and Port Arthur, Texas, and Lake Charles, Louisiana. Kirby Inland Marine provides shifting and fleeting service for its own barges, as well as for customers and third party carriers, transferring barges within the areas noted.

Kirby Inland Marine also provides shore-based barge tankermen to the Company and third parties. Services to the Company and third parties cover the Gulf Coast, mid-Mississippi Valley, and the Ohio River Valley.

San Jac Marine, LLC (“San Jac”), a subsidiary of Kirby Inland Marine, owns and operates a shipyard in Channelview, Texas which builds marine vessels for both inland and coastal applications, and provide maintenance and repair services. Kirby Inland Marine also builds inland towboats and performs routine maintenance and repairs at the San Jac shipyard.

The Company owns a two-thirds interest in Osprey, which transports project cargoes and cargo containers by barge on the United States inland waterway system.

Coastal Operations. The segment’s coastal operations are conducted through wholly owned subsidiaries, Kirby Offshore Marine, LLC (“Kirby Offshore Marine”) and Kirby Ocean Transport Company (“Kirby Ocean Transport”).

Kirby Offshore Marine provides marine transportation of refined petroleum products, petrochemicals and black oil in coastal regions of the United States. The coastal operations are conducted along the eastern seaboard, western seaboard and the Gulf Coast. The Company also operates equipment, to a lesser extent, in the Eastern and Western Canadian Provinces. The tank barges operating are in the 10,000 to 195,000 barrel capacity range and coastal tugboats in the 2,400 to 10,000 horsepower range. Kirby Offshore Marine’s vessels call on various coastal ports from Maine to Texas, servicing refineries, storage terminals and power plants. The Company also services refineries and storage terminals from Southern California to Washington State.

The coastal transportation of refined petroleum products and black oil is impacted by seasonality and is partially dependent on the area of operations. Operations along the West Coast of the United States have been subject to more seasonal variations in demand than the operations along the East Coast and Gulf Coast regions of the United States. Movements of refined petroleum products such as various blends of gasoline are strongest during the summer driving season while heating oil generally increases during the winter months.

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The coastal fleet consists of 28 tank barges with 2.9 million barrels of capacity, primarily transporting refined petroleum products, black oil and petrochemicals. The Company owns all 28 of the coastal tank barges. Of the 28 coastal tank barges, 20 are refined petroleum products and petrochemical barges and 8 are black oil barges. The Company operates 25 coastal tugboats ranging from 2,400 to 11,000 horsepower, of which all 24 are owned by the Company.

Coastal marine transportation services are typically conducted under term contracts, some of which have renewal options, for customers with which the Company has traditionally had long-standing relationships. During 2021, approximately 80% of the coastal marine transportation revenues were under term contracts and 20% were under spot contracts. During 2022, approximately 75% of the coastal marine transportation revenues were under term contracts and 25% were under spot contracts. During 2023, approximately 85% of the coastal marine transportation revenues were under term contracts and 15% were under spot contracts.

Kirby Offshore Marine also operates a fleet of two offshore dry-bulk barge and tugboat units involved in the transportation of sugar and other dry products between Florida and East Coast ports. These vessels have typically operated under term contracts of affreightment of a year or longer.

Kirby Ocean Transport owns and operates a fleet of two offshore dry-bulk barges, two offshore tugboats and one docking tugboat. Kirby Ocean Transport operates primarily under term contracts of affreightment.

Kirby Ocean Transport is also engaged in the transportation of coal, fertilizer, sugar and other bulk cargoes on a spot basis between domestic ports and occasionally the transportation of grain from domestic ports to ports primarily in the Caribbean Basin.

Contracts and Customers

Marine transportation inland and coastal services are conducted under term or spot contracts for customers with whom the Company has traditionally had long-standing relationships. Typically, term contracts range from one to three years, some of which have renewal options. The majority of the marine transportation contracts with its customers by revenue are for terms of one year. Most have been customers of KMT for many years and management anticipates continued relationships; however, there is no assurance that any individual contract will be renewed.

The Company enters into agreements with its customers to transport cargo from a designated origin to a designated destination at a set rate (affreightment) or at a daily rate (time charter). The rate may or may not include escalation provisions to recover changes in specific costs such as fuel. Time charter or contracts of affreightment of one year or greater are considered term contract revenues and agreements of less than a year are included in spot contract revenues. Time charters, which insulate the Company from revenue fluctuations caused by weather and navigational delays and temporary market declines, represented approximately 63% of the marine transportation’s inland revenues under term contracts during 2023, and 58% of the revenue under term contracts during 2022 and 2021. Spot contracts typically involve an agreement with a customer to move cargo from a specific origin to a designated destination for a rate negotiated at the time the cargo movement takes place. Spot contract rates are at the current “market” rate and are subject to market volatility.

The Company typically maintains a higher mix of term contracts to spot contracts to provide the Company with a reasonably predictable revenue stream while maintaining spot market exposure to take advantage of new business opportunities and customers’ peak demands. During 2021, approximately 65% of inland marine transportation revenues were under term contracts and 35% were under spot contracts. During both 2022 and 2023, approximately 60% of inland marine transportation revenues were under term contracts and 40% were under spot contracts. Coastal time charters represented approximately 85% of the marine transportation’s coastal revenues under term contracts in 2021 and approximately 90% of coastal revenues under term contracts in 2022 and 2023.

No single customer of KMT accounted for 10% or more of the Company’s revenues in 2023, 2022, or 2021.

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DISTRIBUTION AND SERVICES

The Company, through its wholly owned subsidiary Kirby Distribution & Services, Inc. and its wholly owned subsidiaries Kirby Engine Systems LLC, (“Kirby Engine Systems”), Stewart & Stevenson LLC (“S&S”), United Holdings LLC (“United”), and Diesel Dash LLC and through Kirby Engine Systems’ wholly owned subsidiaries Marine Systems, Inc. (“Marine Systems”) and Engine Systems, Inc. (“Engine Systems”), serves two markets, commercial and industrial, and oil and gas. The Company sells genuine replacement parts, provides service mechanics to overhaul and repair engines, transmissions, reduction gears and related oilfield service equipment, rebuilds component parts or entire diesel engines, transmissions and reduction gears, electrical motors, drives, and controls, specialized electrical distribution and control systems, energy storage battery systems, and related equipment used in oilfield services, marine, power generation, on-highway, and other commercial and industrial applications. Customers are served through a network of 63 branch locations across 17 states and Colombia, South America, as well as a proprietary on-line marketplace, www.dieseldash.com. The Company manufactures and remanufactures oilfield service equipment, including pressure pumping units, for North American as well as for international oilfield service companies, and oil and gas operator and producer markets. The Company also sells engines, transmissions, power generation systems, and rents equipment including generators, industrial compressors, high capacity lift trucks, and refrigeration trailers for use in a variety of commercial and industrial applications, including for oilfield service and railroad customers.

For the commercial and industrial market, the Company sells Original Equipment Manufacturers (“OEM”) replacement parts and new diesel engines, provides service mechanics and maintains facilities to overhaul and repair diesel engines and ancillary products for marine and on-highway transportation companies, and industrial companies. The Company provides engineering and field services, OEM replacement parts and safety-related products to power generation operators and to the nuclear industry, manufactures engine generator and pump packages for power generation operators and municipalities, offers power generation systems customized for specific commercial and industrial applications, and rents equipment including generators, industrial compressors, high capacity lift trucks, and refrigeration trailers for use in a variety of industrial markets.

For the oil and gas market, the Company sells OEM replacement parts, sells and services diesel engines, pumps and transmissions, manufactures and remanufactures pressure pumping units, manufactures cementing and pumping equipment, as well as coil tubing and well intervention equipment, electric power generation equipment, specialized electrical distribution and control equipment, and high capacity energy storage/battery systems. Customers include oilfield service companies, and oil and gas operators and producers.

No single customer of KDS accounted for 10% or more of the Company’s revenues in 2023, 2022, or 2021. KDS also provides service to KMT, which accounted for approximately 3% of KDS’s 2023 and 2022 revenues, and 2% of the segment's 2021 revenues. Such revenues are eliminated in consolidation and not included in the table below.

The following table sets forth the revenues for KDS (dollars in thousands):

	Year Ended December 31,
	2023		%			2022		%			2021		%
Service and parts	$	1,071,297		78	%	$	962,187		82	%	$	813,875		88	%
Manufacturing		298,406		22			205,600		18			109,867		12
	$	1,369,703		100	%	$	1,167,787		100	%	$	923,742		100	%

Commercial and Industrial Operations

The Company serves the marine, on-highway, power generation, and other commercial and industrial markets primarily in the United States. The commercial and industrial operations represented approximately 59% of the segment’s 2023 revenues.

The Company is engaged in the overhaul and repair of medium-speed and high-speed marine diesel engines and reduction gears, line boring, block welding services and related parts sales for customers in the marine industry. Medium-speed diesel engines have an engine speed of 400 to 1,000 revolutions per minute (“RPM”) with a horsepower range of 800 to 32,000. High-speed diesel engines have an engine speed of over 1,000 RPM and a horsepower range of 50 to 8,375. The Company services medium-speed and high-speed diesel engines utilized in the inland and offshore barge industries. It also services marine equipment and offshore drilling equipment used in the offshore petroleum exploration and oilfield service industry, marine equipment used in the offshore commercial fishing industry, harbor docking vessels, commercial ferries, vessels owned by the United States government and large pleasure crafts.

The Company has marine repair operations throughout the United States providing in-house and in-field repair capabilities and related parts sales. The Company’s emphasis is on service to its customers, and it sends its crews from any of its locations to service customers’ equipment anywhere in the world. The medium-speed operations are located in Houma, Louisiana, Chesapeake, Virginia,

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Paducah, Kentucky, Seattle, Washington, and Tampa, Florida, serving as the authorized distributor for EMD Power Products (“EMD”) throughout the United States. The Company is also a distributor and representative for certain Alfa Laval products in the Midwest and on the East Coast, Gulf Coast, and West Coast. All of the marine locations are authorized distributors for Falk Corporation reduction gears and Oil States Industries, Inc. clutches. The Chesapeake, Virginia operation concentrates on East Coast inland and offshore dry-bulk, tank barge and harbor docking operators, and the United States government. The Houma, Louisiana operation concentrates on the inland and offshore barge and oilfield services industries. The Tampa, Florida operation concentrates on Gulf of Mexico offshore dry-bulk, tank barge and harbor docking operators. The Paducah, Kentucky operation concentrates on the inland river towboat and barge operators and the Great Lakes carriers. The Seattle, Washington operation concentrates on the offshore commercial fishing industry, the offshore barge industry, the United States government, and other customers in Alaska, Hawaii and the Pacific Rim.

The high-speed marine operations are located in Houston, Texas, Houma, Baton Rouge, Belle Chasse and New Iberia, Louisiana, Paducah, Kentucky, Mobile, Alabama, Lodi and Thorofare, New Jersey, and several locations in Florida. The Company serves as a factory-authorized marine dealer for Caterpillar diesel engines in multiple states. The Company also operates factory-authorized full service marine distributorships/dealerships for Cummins, Detroit Diesel, John Deere, MTU, and Volvo Penta, and Kohler diesel engines, as well as Falk, Lufkin and Twin Disc marine gears. High-speed diesel engines provide the main propulsion for a significant amount of the United States flagged commercial vessels and large pleasure craft vessels, other marine applications, including engines for power generators and barge pumps.

The Company distributes, sells parts for and services diesel engines and transmissions for on-highway use and provides in-house and in-field service capabilities. The Company is the largest on-highway distributor for Allison Transmission and Detroit Diesel/Daimler Truck North America, providing parts, service and warranty on engines, transmissions and related equipment in Arkansas, Colorado, Florida, Louisiana, New Mexico, New York, Oklahoma, Texas, Wyoming, and the country of Colombia. The Company also provides similar service for off-highway use and additionally has distributor rights for Deutz and Isuzu diesel engines. Off-highway applications are primarily surface and underground mining equipment, including loaders, crawlers, crushers, power screens, pumps, cranes, generators, and haul trucks, as well as equipment rental.

The Company is engaged in the overhaul and repair of diesel engines and generators, and related parts sales for power generation customers. The Company is also engaged in the sale and distribution of diesel engine parts, engine modifications, generator modifications, controls, governors and diesel generator packages to the nuclear industry. The Company services users of diesel engines that provide emergency standby, peak and base load power generation. The Company also sells power generation systems that are customized for specific applications and the rental of power generation systems.

The Company has power generation operations throughout the United States providing in-house and in-field repair capabilities and products for power generation applications. Through its Rocky Mount, North Carolina operation, the Company serves as the exclusive worldwide distributor of EMD products to the nuclear industry, the worldwide distributor for Woodward, Inc. products to the nuclear industry, the worldwide distributor of Cooper Machinery Services (“Cooper”) products to the nuclear industry and owns the assets and technology necessary to support the Nordberg medium-speed diesel engines used in nuclear applications. In addition, the Rocky Mount operation is an exclusive distributor for Norlake Manufacturing Company transformer products to the nuclear industry, an exclusive distributor of Hannon Company generator and motor products to the nuclear industry, and a non-exclusive distributor of analog Weschler Instruments metering products and an exclusive distributor of digital Weschler metering products to the nuclear industry. The Company is also a non-exclusive distributor of Ingersoll Rand air start equipment to the nuclear industry worldwide.

The Company sells pre-packaged and fabricated power generation systems for emergency, standby and auxiliary power for commercial and industrial applications. The Company also offers rental generator systems from 50 to 2,000 kilowatts of power to a broad range of customers. The Company also is engaged in the rental of industrial compressors, high capacity lift trucks, and refrigeration trailers. In addition, the Company provides accessory products such as cables, hoses, fuel cells, air dryers, air compressor boosters and ground heaters. Lastly, the Company is a dealer for Thermo King refrigeration systems for trucks, railroad cars and other land transportation markets in Texas and Colorado.

Commercial and Industrial Customers

The results of the distribution and services industry are largely tied to the industries it serves and, therefore, are influenced by the cycles of such industries. The Company’s major marine customers include inland and offshore barge operators, oilfield service companies, offshore fishing companies, other marine transportation entities, the United States government and large pleasure crafts. Since the marine business is linked to the relative health of the inland towboat, offshore and coastal tugboat, harbor docking tugboat, offshore oilfield service, oil and gas drilling, offshore commercial fishing industries, Great Lakes ore vessels, dredging vessels, coastal ferries, United States government vessels and the pleasure craft industry, there is no assurance that its present gross revenues can be maintained in the future.

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The Company’s on-highway customers are long-haul and short-haul trucking companies, commercial and industrial companies with truck fleets, buses owned by municipalities and private companies. Off-highway companies include surface and underground mining operations with a large variety of equipment.

The Company’s power generation customers are domestic utilities and the worldwide nuclear power industry, municipalities, universities, medical facilities, data centers, petrochemical plants, manufacturing facilities, shopping malls, office complexes, residential and other industrial users.

The Company’s rental customers are primarily commercial and industrial companies, and residential customers with short-term rental requirements.

Commercial and Industrial Competitive Conditions

The Company’s primary marine competitors are independent distribution and services companies and other factory-authorized distributors, authorized service centers and authorized marine dealers. Certain operators of diesel powered marine equipment also elect to maintain in-house service capabilities. While price is a major determinant in the competitive process, reputation, consistent quality, expeditious service, experienced personnel, access to parts inventories and market presence are also significant factors. A substantial portion of the Company’s business is obtained by competitive bids. However, the Company has entered into service agreements with certain operators of diesel powered marine equipment, providing such operators with one source of support and service for all of their requirements at pre-negotiated prices.

The Company is one of a limited number of authorized resellers of EMD, Caterpillar, Cummins, Detroit Diesel, John Deere, MTU and Volvo Penta parts. The Company is also the marine distributor for Falk and Lufkin reduction gears throughout the United States.

The Company’s primary power generation competitors are other independent diesel service companies and manufacturers. While price is a major determinant in the competitive process, reputation, consistent quality, expeditious service, experienced personnel, access to parts inventories and market presence are also significant factors. A substantial portion of the Company’s business is obtained by competitive bids.

As noted above, the Company is the exclusive worldwide distributor of EMD, Cooper, Woodward, Nordberg, Norlake and Hannon parts for the nuclear industry, and non-exclusive distributor of Weschler parts and Ingersoll Rand air start equipment for the nuclear industry. Specific regulations relating to equipment used in nuclear power generation require extensive testing and certification of replacement parts. OEM parts need to be properly tested and certified for nuclear applications.

Oil and Gas Operations

The Company is engaged in the distribution and service of high-speed diesel engines, pumps and transmissions, and the manufacture and remanufacture of oilfield service equipment. The oil and gas operations represented approximately 41% of the segment’s 2023 revenues. The Company offers custom fabricated oilfield service equipment that is fully tested and field ready. The Company manufactures and remanufactures oilfield service equipment, including pressure pumping units, nitrogen pumping units, cementers, hydration equipment, mud pumps and blenders, coil tubing, well intervention equipment, electric power generation equipment, specialized electrical distribution and control equipment, and high capacity energy storage/battery systems. The Company sells OEM replacement parts, and sells and services diesel engines, electric drives, motors and controls, pumps and transmissions, and offers in-house and in-field service capabilities. The Company is the largest off-highway distributor for Allison Transmission and a major distributor for MTU in North America.

The Company’s manufacturing and remanufacturing facilities and service facilities are based in Houston, Texas and Oklahoma City, Oklahoma, both key oil and gas producing regions.

Oil and Gas Customers

The Company’s major oil and gas customers include large and mid-cap oilfield service providers, oil and gas operators and producers. The Company has long standing relationships with most of its customers. Since the oil and gas business is linked to the oilfield services industry, and oil and gas operators and producers, there is no assurance that its present gross revenues can be maintained in the future. The results of the Company’s oil and gas distribution and services operations are largely tied to the industries it serves and, therefore, are influenced by the cycles of such industries.

Oil and Gas Competitive Conditions

The Company’s primary competitors in the oil and gas market are other oilfield equipment manufacturers and remanufacturers, and equipment service companies. While price is a major determinant in the competitive process, equipment availability, reputation,

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consistent quality, expeditious service, experienced personnel, access to parts inventories and market presence are also significant factors. A substantial portion of the Company’s business is obtained by competitive bids.

Governmental Regulations

General. The Company’s operations, products, and services are subject to various government regulations, which vary based upon its operations across and within its business segments.

In KMT, the Company’s marine transportation operations are subject to regulation by the United States Coast Guard (“USCG”), federal laws, state laws, the laws of other countries when operating in their waters, and certain international conventions. The agencies establish safety requirements and standards and are authorized to investigate incidents.

Most of the Company’s tank barges are inspected by the USCG and carry certificates of inspection. The Company’s inland and coastal towing vessels and coastal dry-bulk barges are also subject to USCG regulations. The USCG has enacted safety regulations governing the inspection, standards, and safety management systems of towing vessels. The regulations also create many new requirements for design, construction, equipment, and operation of towing vessels. The USCG regulations supersede the jurisdiction of the United States Occupational Safety and Health Administration (“OSHA”) and any state regulations on vessel design, construction, alteration, repair, maintenance, operation, equipping, personnel qualifications and manning. The regulations requiring towing vessels to obtain a certificate of inspection became effective for existing towing vessels on July 20, 2018. Other portions of the regulations were phased in following the July 20, 2018 effective date through July 19, 2022, by which time the Company was in full compliance.

All of the Company’s coastal tugboats and coastal tank and dry-bulk barges are built to American Bureau of Shipping (“ABS”) classification standards and/or statutory requirements issued by the USCG, and are inspected periodically by ABS and/or the USCG to maintain the vessels in class and compliant with all U.S. statutory requirements, as applicable to the vessel. The crews employed by the Company aboard inland and coastal vessels, including captains, pilots, engineers, tankermen and ordinary seamen, are licensed by the USCG.

The Company is required by various governmental agencies to obtain licenses, certificates and permits for its vessels depending upon such factors as the cargo transported, the waters in which the vessels operate and other factors. The Company believes that its vessels have obtained and can maintain all required licenses, certificates and permits required by such governmental agencies for the foreseeable future. The Company’s failure to maintain these authorizations could adversely impact its operations.

The Company believes that additional security and environmental related regulations relating to contingency planning requirements could be imposed on the marine industry. Generally, the Company endorses the anticipated additional regulations and believes it is currently operating to standards at least equal to anticipated additional regulations.

When the Company does operate in foreign jurisdictions, it is subject to the legal and regulatory requirements of those jurisdictions in addition to those generally applicable to the Company's domestic operations. This is primarily applicable to the coastal business of the KMT segment and Colombia branches in the KDS segment. Further, to the extent the Company does business with foreign counterparties, it is subject to additional rules and regulations, in particular, with regard to import and export compliance and the Foreign Corrupt Practices Act (“FCPA”), or similar local applicable anti-bribery laws. The Company provides anti-corruption training to all of its employees.

Jones Act. The Jones Act is a federal cabotage law that restricts domestic marine transportation in the United States to vessels built and registered in the United States and manned, owned and operated by United States citizens. For a corporation to qualify as a United States citizen for the purpose of domestic trade, it has to be 75% owned and controlled by United States citizens within the meaning of the Jones Act. The Company monitors its citizenship status and meets the requirements of the Jones Act for its owned and operated vessels.

Compliance with United States ownership requirements of the Jones Act is important to the operations of the Company, and a violation of the Jones Act could have a material negative effect on the Company and its vessels’ ability to operate. The Company monitors the citizenship of its employees and stockholders and complies with United States build requirements.

User Taxes. Federal legislation requires that inland marine transportation companies pay a user tax based on propulsion fuel used by vessels engaged in trade along the inland waterways that are maintained by the United States Army Corps of Engineers. Such user taxes are designed to help defray the costs associated with replacing major components of the inland waterway system, such as locks and dams. A significant portion of the inland waterways on which the Company’s vessels operate is maintained by the Army Corps of Engineers.

The Company presently pays a federal fuel user tax of 29.1 cents per gallon consisting of a 0.1 cent per gallon leaking underground storage tank tax and 29 cents per gallon waterways user tax.

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Security Requirements. The Maritime Transportation Security Act of 2002 requires, among other things, submission to and approval by the USCG of vessel and waterfront facility security plans (“VSP” and “FSP”, respectively). The Company maintains approved VSP and FSP and is operating in compliance with the plans for all of its vessels and facilities that are subject to the requirements.

Environmental Regulations

The Company’s operations are affected by various regulations and legislation enacted for protection of the environment by the United States government, as well as many coastal and inland waterway states and international jurisdictions to the extent that the Company’s vessels transit in international waters or the Company operates in such jurisdictions. Government regulations require the Company to obtain permits, licenses and certificates for the operation of its vessels and its facilities in both KMT and KDS. Failure to maintain necessary permits or approvals could require the Company to incur costs or temporarily suspend operation of one or more of its vessels or other facilities. Violations of these laws may result in civil and criminal penalties, fines, or other sanctions.

Water Pollution Regulations. The Federal Water Pollution Control Act of 1972, as amended by the Clean Water Act of 1977 (“Clean Water Act”), the Comprehensive Environmental Response, Compensation and Liability Act of 1981 (“CERCLA”) and the Oil Pollution Act of 1990 (“OPA”) impose strict prohibitions against the discharge of oil and its derivatives or hazardous substances into the navigable waters of the United States. These acts impose civil and criminal penalties for any prohibited discharges and impose substantial strict liability for cleanup of these discharges and any associated damages. Certain states also have water pollution laws that prohibit discharges into waters that traverse the state or adjoin the state, and impose civil and criminal penalties and liabilities similar in nature to those imposed under federal laws.

The OPA and various state laws of similar intent substantially increased over historic levels the statutory liability of owners and operators of vessels for oil spills, both in terms of limit of liability and scope of damages.

The Company manages its exposure to losses from potential discharges of pollutants through the use of well-maintained and equipped vessels, through safety, training and environmental programs, and through the Company’s insurance program. There can be no assurance, however, that any new regulations or requirements or any discharge of pollutants by the Company will not have an adverse effect on the Company.

Clean Water Act. The Clean Water Act establishes the National Pollutant Discharge Elimination System (“NPDES”) permitting program which regulates discharges into navigable waters of the United States. The United States Environmental Protection Agency (“EPA”) regulates the discharge of ballast water and other substances in United States waters under the Clean Water Act. Pursuant to the NPDES program, effective February 6, 2009, the EPA issued regulations requiring vessels 79 feet in length or longer to comply with a Vessel General Permit authorizing ballast water discharges and other discharges incidental to the operation of the vessels. The EPA regulations also imposed technology and water quality based effluent limits for certain types of discharges and established specific inspection, monitoring, recordkeeping and reporting requirements for vessels to ensure effluent limitations are met. The Vessel Incidental Discharge Act (“VIDA”), signed into law on December 4, 2018, established a new framework for the regulation of vessel incidental discharges under the Clean Water Act. VIDA requires the EPA to develop national performance standards for those discharges within two years of enactment and requires the USCG to develop implementation, compliance, and enforcement regulations within two years of the EPA’s promulgation of standards. Under VIDA, all provisions of the Vessel General Permit which became effective December 19, 2013, remain in force and effect until the USCG regulations are finalized. The Company maintains Vessel General Permits and has established recordkeeping and reporting procedures in compliance with the EPA’s interim requirements.

The USCG adopted regulations on ballast water management treatment systems establishing a standard for the allowable concentration of living organisms in certain vessel ballast water discharged in waters of the United States under the National Invasive Species Act. The regulations include requirements for the installation of engineering equipment to treat ballast water by establishing an approval process for ballast water management systems (“BWMS”). The BWMS implementation was suspended until December 2016 at which time the USCG approved manufacturers’ systems that met the regulatory discharge standard equivalent to the International Maritime Organization’s D-2 standard. The phase-in schedule for those existing vessels requiring a system to install a BWMS is dependent on vessel build date, ballast water capacity, and drydock schedule. Compliance with the ballast water treatment regulations requires the installation of equipment on some of the Company’s vessels to treat ballast water before it is discharged. The installation of BWMS equipment has required and continues to require significant capital expenditures in accordance with the compliance schedule established by the USCG in 33 CFR 151 to complete the installation of the approved system on those existing vessels that require a system in order to comply with the BWMS regulations. During 2024, the Company expects to complete installation of an approved BWMS on the last such barge currently in its fleet.

Financial Responsibility Requirement. Commencing with the Federal Water Pollution Control Act of 1972, as amended, vessels over 300 gross tons operating in the Exclusive Economic Zone of the United States have been required to maintain evidence of financial ability to satisfy statutory liabilities for oil and hazardous substance water pollution. This evidence is in the form of a Certificate of Financial Responsibility (“COFR”) issued by the USCG. The majority of the Company’s tank barges are subject to this COFR

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requirement, and the Company has fully complied with this requirement since its inception. The States of Alaska, California, and Washington have implemented state financial responsibility requirements. Currently, the States of California and Alaska require a COFR and the State of Washington is in the process of implementing a COFR requirement to be effective during the course of 2024. The Company does not foresee any current or future difficulty in maintaining the COFR certificates or meeting financial responsibility requirements under current federal or state rules.

Clean Air Regulations. The Federal Clean Air Act of 1979 (“CAA”) requires states to draft State Implementation Plans (“SIPs”) under the National Ambient Air Quality Standards designed to reduce atmospheric pollution for six common air pollutants to levels mandated by this act. The EPA designates areas in the United States as meeting or not meeting the standards. Several SIPs implement the regulation of barge loading and discharging emissions at waterfront facilities as a measure to meet the CAA standard. The implementation of these regulations requires a reduction of hydrocarbon emissions released into the atmosphere during the loading of most petroleum products and the degassing and cleaning of barges for maintenance or change of cargo. These regulations require vessel operators that operate in states with areas of nonattainment of air quality standards under the CAA to install vapor control equipment on their barges. The Company expects that future emission regulations will be developed and will apply this same technology to many chemicals that are handled by barge. Most of the Company’s barges engaged in the transportation of petrochemicals, chemicals and refined petroleum products are already equipped with vapor control systems. KDS, particularly in its oil and gas equipment service and manufacturing and the power generation businesses, must closely adhere to federal regulatory requirements relating to emissions for stationary and non-road engines. Although a risk exists that new regulations could require significant capital expenditures by the Company and otherwise increase the Company’s costs, the Company believes that, based upon the regulations that have been proposed thus far, no material capital expenditures beyond those currently contemplated by the Company and no material increase in costs are likely to be required.

Contingency Plan Requirement. The OPA and several state statutes of similar intent require the majority of the vessels and terminals operated by the Company to maintain approved oil spill contingency plans as a condition of operation. The Company has approved plans that comply with these requirements. The OPA also requires development of regulations for hazardous substance spill contingency plans. The USCG has not yet promulgated these regulations; however, the Company anticipates that they will not be more difficult to comply with than the oil spill plans.

Occupational Health Regulations. The Company’s inspected vessel operations are primarily regulated by the USCG for occupational health standards. Uninspected vessel operations, the Company’s shore-based personnel, and employees in the Company’s KDS segment are subject to OSHA regulations. The Company believes that it is in compliance with the provisions of the regulations that have been adopted and does not believe that the adoption of any further regulations will impose additional material requirements on the Company. There can be no assurance, however, that claims will not be made against the Company for work related illness or injury, or that the further adoption of health regulations will not adversely affect the Company.

Insurance. The Company’s marine transportation operations are subject to the hazards associated with operating vessels carrying large volumes of bulk cargo in a marine environment. These hazards include the risk of loss of or damage to the Company’s vessels, damage to third parties as a result of collision, fire or explosion, adverse weather conditions, loss or contamination of cargo, personal injury of employees and third parties, and pollution and other environmental damages. The Company maintains hull, liability, general liability, workers compensation and pollution liability insurance coverage against these hazards. For shipyard operations, the Company has ship repairer’s liability and builder’s risk insurance. The Company uses a Texas domiciled wholly owned insurance subsidiary, Adaptive KRM, LLC, to provide cost effective risk transfer options to insure certain exposures of the Company and certain of its subsidiaries in KMT and KDS. The Company also maintains insurance to address liabilities arising in connection with KDS.

Environmental Protection. The Company utilizes several programs to further its commitment to environmental responsibility in its operations. Environmental compliance audits, performed with internal and external resources, are performed regularly on the Company's operations. Additionally, the Company employs third party expertise to conduct safety performance, safety management system, and environmental audits on its barge cleaning and shipyard vendors. The Company participates in the American Waterways Operators Responsible Carrier program, which drives continuous improvement towards reducing the barge industry’s impact on the environment. It is also a member of the Blue Sky Maritime Coalition and other organizations focused on reducing greenhouse gas emissions.

Safety. The Company manages its exposure to the hazards associated with its business through safety, training and preventive maintenance efforts. The Company emphasizes its safety commitment through programs oriented toward extensive monitoring of safety performance for the purpose of identifying trends and initiating corrective action, and for continuously improving employee safety behavior and performance.

Training. The Company believes that among the major elements of a successful and productive workforce are effective training programs. The Company also believes that training in the proper performance of a job enhances both the safety and quality of the service provided. New technology, regulatory compliance, personnel safety, quality and environmental concerns create additional demands for training. Refer to Human Capital below for further discussion regarding training programs the Company has developed and instituted.

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Quality. Kirby Inland Marine has made a substantial commitment to the implementation, maintenance, and improvement of quality assurance systems. Kirby Offshore Marine is certified under ABS ISM standards. These Quality Assurance Systems and certification have enabled both shore and vessel personnel to effectively manage the changes which occur in the working environment, as well as enhancing the Company’s safety and environmental performance.

Human Capital

Employment. The Company has approximately 5,450 employees, the large majority of whom are in the United States. The large majority of non-vessel employees work full-time. Vessel employees work varying schedules according to their assignments. The Company has approximately 110 general corporate employees. The Company supports its employees by providing competitive pay and benefits, training, and a respectful and inclusive culture.

KMT has approximately 3,070 employees, of which approximately 2,350 are vessel crew members. None of the segment’s inland operations are subject to collective bargaining agreements. The segment’s coastal operations include approximately 413 vessel employees, some of which are subject to collective bargaining agreements in certain geographic areas. Approximately 217 Kirby Offshore Marine vessel crew members are subject to a collective bargaining agreement with the Richmond Terrace Bargaining Unit in effect through August 31, 2025. In addition, approximately 108 vessel crew members of Penn Maritime Inc., a wholly owned subsidiary of Kirby Offshore Marine, are represented by the Seafarers International Union under a collective bargaining agreement in effect through May 1, 2025.

KDS has approximately 2,270 employees. None of the United Holdings and Kirby Engine Systems operations are subject to collective bargaining agreements. Approximately 50 S&S employees in New Jersey are subject to a collective bargaining agreement with the Local 15C, International Union of Operating Engineers, AFL-CIO that expires in October 2028. The remaining S&S employees are not subject to collective bargaining agreements.

Training and Development. The Company strives to provide its employees with a rewarding work environment, including the opportunity for success and an opportunity for personal and professional development. The development of its people is a key factor in the Company’s employee retention and satisfaction. Its technical and skill training has always been a differentiator and has facilitated the recruitment of new trainees.

For the marine business, the Company’s training facility includes state-of-the-art equipment and instruction aids, including a full bridge wheelhouse simulator, a working towboat, two tank barges, and a tank barge simulator for tankermen training. During 2023, approximately 1,750 certificates were issued for the completion of courses at the training facility, of which approximately 930 were USCG approved classes and the balance were employee development and Company required classes, including leadership, communication, and navigation courses. The Company uses the Seaman’s Church Institute as an additional training resource for its wheelhouse crewmembers. The marine segment provides a clear career progression for vessel personnel from entry level deckhand to captain and regularly reviews promotions from one level to another.

In distribution and services, the Company operates regional training centers providing instructor-led, skill-based training classes to certify its technicians to work on diesel engines, transmissions, and power generation equipment. KDS has multiple career progressions within its numerous job groups. In 2022, KDS launched an apprentice program at various locations. The Company continues to recruit and train apprentices for technical roles.

The Company's leadership and managerial training includes an online training curriculum that is available to both supervisory employees and those employees that aspire to move into such roles in the future. It includes a series of classes focused on management essentials which provide in-depth education in specific subjects such as leadership, strategic thinking, coaching and people development, decision making, problem solving, and communication.

In addition, the Company facilitates many training courses that cover a range of topics that enhance specific skill sets, increase productivity, and educate employees about safety and team morale across both business segments. Training classes include environmental, health, and safety classes, compliance, leadership, and general business skills related courses. Environmental, health, and safety topics include defensive and distracted driving, first aid basic and medical emergencies, global safety principles, oil management, and hazardous substances training. Compliance topics include anti-corruption and anti-human trafficking training, cybersecurity awareness, business ethics, compliance, and promoting diversity. Skill related topics include business writing, risk-based thinking, initiating and planning a project, and transitioning into a project management role.

Diversity, Equity, and Inclusion. The Company believes that its culture of inclusion and diversity contributes to a strong workforce that meets its customer’s expectations and business objectives. The Company works diligently to attract the best talent from a diverse range of sources in order to meet the current and future demands of its business. The Company has established relationships with trade schools, world-class universities, professional associations and industry groups to proactively attract talent.

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The Company has also implemented several measures and development programs that include training to help increase awareness and drive inclusive behaviors, identifying areas for improvement and providing oversight for hiring, promotions, and mentoring. In 2021, the Company instituted an organization-wide training initiative that expanded the understanding and awareness of diversity and inclusion. Over 5,000 employees successfully completed this training. In 2022, the Company tied diversity objectives as a factor in its safety, operations and ESG components of its short-term performance goals under the Annual Incentive Plan.

Succession Planning. Succession planning is a key responsibility of the CEO and the Vice President – Human Resources and is a critical annual process for the Company’s senior management and its Board. Senior management reviews their succession plans regularly throughout the year and on an annual basis provides the Board an in-depth review of the top three levels of management. This process looks at qualifications, time in role, readiness to advance, diversity, and required development. The Board engages with many of these individuals through presentations on a variety of projects and subjects. The development initiatives undertaken with those in the succession plan may comprise of 360-degree feedback, high level post graduate work, targeted development work around strengthening a needed competency, or additional industry exposure.

Culture, Engagement, and Social Responsibility. The Company recognizes the importance of employee engagement and has implemented a regular process of surveying its employees to obtain their feedback on both what is working well and areas of improvement. One of the main take-aways from the 2023 survey was 90% of employees surveyed agree that Kirby is committed to Employee Safety. In addition, employees believe the Company operates with strong values, has a strong safety culture, and would recommend working for the Company to others.

The Company provides its employees with a rewarding work environment, which includes access to resources for personal and professional development. The Company often participates in community organizations, service projects and matches employee charitable contributions. Through the Kirby Disaster Relief Fund, the Company supports employees in need following natural disasters and other qualified hardships. The Company provides employees with tuition reimbursement and college scholarships for the children of non-executive employees. In addition to standard health and welfare benefits, the Company offers wellness incentives and initiatives that encourages employees to receive an annual wellness checkup.

Information about the Company’s Executive Officers

The executive officers of the Company are as follows:

Name	Age	Positions and Offices
David W. Grzebinski	62	President and Chief Executive Officer
Raj Kumar	51	Executive Vice President and Chief Financial Officer
Christian G. O’Neil	51	President – Kirby Inland Marine, Kirby Offshore Marine, San Jac Marine, LLC, and Kirby Offshore Wind, LLC
Dorman L. Strahan	67	President – Kirby Engine Systems
Ronald A. Dragg	60	Vice President, Controller and Assistant Secretary
Amy D. Husted	55	Vice President, General Counsel and Secretary
Julie M. Kruger	43	Vice President – Human Resources
Scott P. Miller	45	Vice President and Chief Information Officer
Kurt A. Niemietz	51	Vice President – Investor Relations and Treasurer
William M. Woodruff	63	Vice President – Public and Governmental Affairs

No family relationship exists among the executive officers or among the executive officers and the directors. Officers are elected to hold office until the annual meeting of directors, which immediately follows the annual meeting of stockholders, or until their respective successors are elected and have qualified.

David W. Grzebinski is a Chartered Financial Analyst and holds a Master of Business Administration degree from Tulane University and a degree in chemical engineering from the University of South Florida. He has served as President and Chief Executive Officer since April 2014. He served as President and Chief Operating Officer from January 2014 to April 2014 and as Chief Financial Officer from March 2010 to April 2014. He served as Chairman of Kirby Offshore Marine from February 2012 to April 2013 and served as Executive Vice President from March 2010 to January 2014. Prior to joining the Company in February 2010, he served in various operational and financial positions since 1988 with FMC Technologies Inc. (“FMC”), including Controller, Energy Services, Treasurer, and Director of Global SAP and Industry Relations. Prior to joining FMC, he was employed by Dow Chemical Company in manufacturing, engineering and financial roles.

Raj Kumar is a member of CPA Australia and holds a Master of Business Administration degree from Columbia University in New York City and a Bachelor of Business in Accounting degree from Deakin University in Australia. He has served as Executive Vice President and Chief Financial Officer since November 2021. Prior to joining the Company, Mr. Kumar served as Vice President and

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Chief Financial Officer of Dril-Quip, Inc. from 2020 to 2021, Vice President and Chief Accounting Officer from 2019 to 2020, and Vice President and Treasurer from 2017 to 2019. Prior to joining Dril-Quip, he served as Vice President Finance at Frank’s International from 2015 to 2017. Prior to that, he served as a segment controller at LyondellBasell and in Division CFO, treasury, strategic planning and corporate development positions at FMC and Dell Inc.

Christian G. O’Neil holds a Master of Business Administration degree from Rice University, a doctorate of jurisprudence from Tulane University and a bachelor of arts degree from Southern Methodist University. He has served as President of Kirby Inland Marine and Kirby Offshore Marine since January 2018, as President of San Jac Marine, LLC since October 2018, and President of Kirby Offshore Wind, LLC since March 2021. He served as Executive Vice President and Chief Operating Officer of Kirby Inland Marine and Kirby Offshore Marine from May 2016 to January 2018. He also served as Executive Vice President – Commercial Operations of Kirby Inland Marine and Kirby Offshore Marine from April 2014 to May 2016, Vice President – Human Resources of the Company from May 2012 to April 2014, Vice President – Sales for Kirby Inland Marine from 2009 to 2012 and President of Osprey from 2006 through 2008. He has also served in various sales and business development roles at the Company and Osprey. Prior to joining the Company, he served as Sales Manager and Fleet Manager at Hollywood Marine, Inc. (“Hollywood Marine”) after joining Hollywood Marine in 1997 which was subsequently merged into the predecessor of Kirby Inland Marine.

Dorman L. Strahan attended Nicholls State University and has served the Company as President of Kirby Engine Systems since May 1999, President of Marine Systems since 1986 and President of Engine Systems since 1996. After joining the Company in 1982 in connection with the acquisition of Marine Systems, he served as Vice President of Marine Systems until 1985.

Ronald A. Dragg is a Certified Public Accountant and holds a Master of Science in Accountancy degree from the University of Houston and a degree in finance from Texas A&M University. He has served the Company as Vice President, Controller and Assistant Secretary since April 2014. He also served as Vice President and Controller from January 2007 to April 2014, as Controller from November 2002 to January 2007, Controller – Financial Reporting from January 1999 to October 2002, and Assistant Controller – Financial Reporting from October 1996 to December 1998. Prior to joining the Company, he was employed by Baker Hughes Incorporated.

Amy D. Husted holds a doctorate of jurisprudence from South Texas College of Law and a Bachelor of Science degree in political science from the University of Houston. She has served the Company as Vice President, General Counsel and Secretary since April 2019. She also served as Vice President and General Counsel from January 2017 to April 2019, Vice President – Legal from January 2008 to January 2017 and Corporate Counsel from November 1999 through December 2007. Prior to joining the Company, she served as Corporate Counsel of Hollywood Marine from 1996 to 1999 after joining Hollywood Marine in 1994.

Julie M. Kruger holds a Bachelor of Science degree from Texas A&M University. She has served the Company as Vice President Human Resources since March 2023. She served as Senior Director Human Resources from May 2020 to March 2023. Prior to joining the Company, she served in a variety of roles in human resources at increasing levels of leadership at Key Energy Services from July 2007 to February 2020, including as Vice President Human Resources from March 2019 to February 2020 and Senior Human Resources Director from November 2016 to March 2019.

Scott P. Miller holds a Bachelor of Science in Management of Information Systems from Louisiana State University and a Master of Business Administration degree from the University of Houston. He has served as Vice President and Chief Information Officer since April 2019. Prior to joining the Company, he was employed by Key Energy Services, Inc. from May 2006 to March 2019, serving in various senior leadership roles including Managing Director of Strategy, Vice President and Chief Information Officer from March 2013 to December 2015 and as Senior Vice President, Operations Services and Chief Administrative Officer from January 2016 to March 2019.

Kurt A. Niemietz holds a Master of Business Administration degree from St. Mary’s University and a degree in accounting from the University of Texas at San Antonio. He has served the Company as Vice President - Investor Relations and Treasurer since July 2022. He also served as Vice President and Treasurer from April 2019 to July 2022. Prior to joining the Company, he was employed by Pacific Drilling from 2013 to 2019, serving in various roles of increasing responsibility, including Treasurer from 2017 to 2019, and in various financial positions with FMC, from 2006 to 2013. Prior to joining FMC, he was employed by Austin, Calvert & Flavin as a buy-side equity analyst.

William M. Woodruff holds a doctorate of jurisprudence from the University of Houston Law Center and a bachelor of science degree from Texas A&M University. He has served as Vice President – Public and Governmental Affairs since October 2017. He served as Director – Public & Government Affairs from 2014 to October 2017 after joining the Company as Director – Government Affairs in 2004. Prior to joining the Company, he was a maritime lawyer in private practice and Vice President and General Counsel of Coastal Towing, Inc.

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Item 1A. Risk Factors

In addition to the other information set forth elsewhere in this annual report, the following risk factors should be considered carefully when evaluating the Company, as its businesses, results of operations, or financial condition could be materially adversely affected by any of these risks. The following discussion does not attempt to cover factors, such as trends in the United States and global economies or the level of interest rates, among others, that are likely to affect most businesses.

Marine Transportation Segment Risk Factors

The Inland Waterway infrastructure is aging and may result in increased costs and disruptions to KMT. Maintenance of the United States inland waterway system is vital to the Company’s operations. The system is composed of over 12,000 miles of commercially navigable waterway, supported by over 240 locks and dams designed to provide flood control, maintain pool levels of water in certain areas of the country and facilitate navigation on the inland river system. The United States inland waterway infrastructure is aging, with more than half of the locks over 50 years old. As a result, due to the age of the locks, scheduled and unscheduled maintenance outages may be more frequent in nature, resulting in delays and additional operating expenses. Currently, 35% of the cost of new construction and major rehabilitation of locks and dams is paid by marine transportation companies through a 29 cent per gallon waterway user tax and the remaining 65% of waterway infrastructure and improvement is paid from general federal tax revenues. Failure of the federal government to adequately fund infrastructure maintenance and improvements in the future would have a negative impact on the Company’s ability to deliver products for its customers on a timely basis. In addition, any additional user taxes that may be imposed in the future to fund infrastructure improvements would increase the Company’s operating expenses.

The Company could be adversely impacted by a marine accident or spill event. A marine accident or spill event could close a portion of the inland waterway system or a coastal area of the United States for an extended period of time. Although statistically marine transportation is the safest means of surface transportation of bulk commodities, accidents do occur, both involving Company equipment and equipment owned by other marine operators.

The Company transports a wide variety of petrochemicals, black oil, refined petroleum products and agricultural chemicals throughout the Mississippi River System, on the Gulf Intracoastal Waterway, and coastwise along all three United States coasts. The Company manages its exposure to losses from potential unauthorized discharges of pollutants through the use of well-maintained and equipped tank barges and towing vessels, through safety, training and environmental programs, and through the Company’s insurance program, but a discharge of pollutants by the Company could have an adverse effect on the Company. Risks may arise for which the Company may not be insured. Claims covered by insurance are subject to deductibles, the aggregate amount of which could be material, and certain policies impose limitations on coverage. Existing insurance coverage may not be able to be renewed at commercially reasonable rates or coverage capacity for certain risks may not be available or adequate to cover future claims. If a loss occurs that is partially or completely uninsured, or the carrier is unable or unwilling to cover the claim, the Company could be exposed to liability.

KMT is dependent on its ability to adequately crew its towing vessels. The Company’s vessels are crewed with employees who are licensed or certified by the USCG, including its captains, pilots, engineers and tankermen. The success of KMT is dependent on the Company’s ability to adequately crew its vessels. As a result, the Company invests significant resources in training its crews and providing crew members an opportunity to advance from a deckhand to the captain of a Company towboat or tugboat. Inland crew members generally work rotations such as 20 days on, 10 days off rotation, or a 30 days on, 15 days off rotation. For the coastal fleet, crew members are generally required to work rotations such as 14 days on, 14 days off rotation, a 21 days on, 21 days off rotation or a 30 days on, 30 days off rotation, dependent upon the location. The nature of crewmember work schedules and assignments away from home for extended periods require special recruiting and at times it can be difficult to find candidates. With ongoing retirements and competitive labor pressure in KMT, the Company continues to monitor and implement market competitive pay practices. The Company also utilizes an internal development program to train Maritime Academy graduates for vessel leadership positions.

KMT has approximately 3,070 employees, of which approximately 2,350 are vessel crew members. None of the segment’s inland operations are subject to collective bargaining agreements. The segment’s coastal operations include approximately 413 vessel employees, of whom approximately 325 are subject to collective bargaining agreements in certain geographic areas. Any work stoppages or labor disputes could adversely affect coastal operations in those areas. While the COVID-19 pandemic caused some crewing issues, the Company was able to manage its operations with limited vessel delays and disruption of services, including some loss of revenue and incremental costs in the Company’s inland and coastal businesses. The Company expects that it would be able to similarly manage its operations in the future were an event of similar impact to occur again, but there is no guarantee that it would be able to do so.

KMT is subject to the Jones Act. KMT competes principally in markets subject to the Jones Act, a federal cabotage law that restricts domestic marine transportation in the United States to vessels built and registered in the United States, and manned, owned and operated by United States citizens. The Company presently meets all of the requirements of the Jones Act for its owned and operated vessels. The loss of Jones Act status could have a significant negative effect on the Company. The requirements that the Company’s vessels be United States built and manned by United States citizens, the crewing requirements and material requirements of the USCG, and the

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application of United States labor and tax laws increases the cost of United States flagged vessels compared to comparable foreign flagged vessels. The Company’s business could be adversely affected if the Jones Act or international trade agreements or laws were to be modified or waived as to permit foreign flagged vessels to operate in the United States as these vessels are not subject to the same United States government imposed regulations, laws, and restrictions. Since the events of September 11, 2001, the United States government has taken steps to increase security of United States ports, coastal waters and inland waterways. The Company believes that it is unlikely that the current cabotage provisions of the Jones Act would be eliminated or significantly modified in a way that has a material adverse impact on the Company in the foreseeable future.

The Secretary of Homeland Security is vested with the authority and discretion to waive the Jones Act to such extent and upon such terms as the Secretary may prescribe whenever the Secretary deems that such action is necessary in the interest of national defense. On September 8, 2017, following Hurricanes Harvey and Irma, the Department of Homeland Security issued a waiver of the Jones Act for a 7-day period for shipments from New York, Pennsylvania, Texas and Louisiana to South Carolina, Georgia, Florida and Puerto Rico. The waiver was specifically tailored to address the transportation of refined petroleum products due to disruptions in hurricane-affected areas. On September 11, 2017, the waiver was extended for 11 days and expanded to include additional states. Following Hurricane Maria, on September 28, 2017, the Department of Homeland Security issued a waiver of the Jones Act for movement of products shipped from United States coastwise points to Puerto Rico through October 18, 2017. Two limited waivers of the Jones Act were granted in connection with the shutdown of the Colonial Pipeline in May 2021. In connection with recovery from Hurricane Fiona, in September and October 2022, two limited waivers of the Jones Act were granted to allow diesel and liquefied natural gas deliveries to Puerto Rico. Waivers of the Jones Act, whether in response to natural disasters or otherwise, could result in increased competition from foreign tank vessel operators, which could negatively impact KMT.

KMT is subject to extensive regulation by the USCG, federal laws, other federal agencies, various state laws, the laws of other countries when operating in their waters, and certain international conventions, as well as numerous environmental regulations. The majority of the Company’s vessels are subject to inspection by the USCG and carry certificates of inspection. The crews employed by the Company aboard vessels are licensed or certified by the USCG. The Company’s marine transportation operations are subject to laws of other countries when operating in their waters. The Company is required by various governmental agencies to obtain licenses, certificates and permits for its owned and operated vessels. The Company’s operations are also affected by various United States and state regulations and legislation enacted for protection of the environment. The Company incurs significant expenses and capital expenditures to comply with applicable laws and regulations and any significant new regulation or legislation, including climate change laws or regulations, could have an adverse effect on the Company.

KMT is subject to natural gas and crude oil prices as well as the volatility of their prices as well as the volatility in production of refined products and petrochemicals in the United States. For 2023, 51% of KMT’s revenues were from the movement of petrochemicals, including the movement of raw materials and feedstocks from one refinery or petrochemical plant to another, as well as the movement of more finished products to end users and terminals for export. As a result of the COVID-19 pandemic and petrochemical and refinery plant shutdowns, 2020 and 2021 petrochemical and refined products volumes decreased relative to 2019. Volumes began to recover in 2021 and have continued to increase in 2022 and 2023 as economic activity improved. The United States petrochemical industry continues to benefit from a low-cost domestically produced natural gas feedstock advantage, producing strong volumes of raw materials and intermediate products for transportation between Gulf Coast petrochemical plants and the transportation of more finished products to terminals for both domestic consumers and for export destinations. In addition, eight new United States petrochemical projects, including expansion of existing plants, were completed during 2022, with an additional five projects completed during 2023 and four scheduled to be completed in 2024. These projects should provide additional movements for KMT. Higher natural gas and crude oil prices are generally better for the Company’s businesses; however, higher natural gas prices and other factors could negatively impact the United States petrochemical industry and its production volumes, which could negatively impact the Company.

Demand for tank barge transportation services is driven by the production of volumes of the bulk liquid commodities such as petrochemicals, black oil and refined petroleum products that the Company transports by tank barge. This production can depend on the prevailing level of natural gas and crude oil prices, as well as the volatility of their prices. In general, lower energy prices are good for the United States economy and typically translate into increased petrochemical and refined product demand and therefore increased demand for tank barge transportation services. However, during 2016 and 2017 lower crude oil prices resulted in a decline in domestic crude oil and natural gas condensate production and reduced volumes to be transported by tank barge. The Company estimates that at the beginning of 2015 there were approximately 550 inland tank barges and 35 coastal tank barges in the 195,000 barrels or less category transporting crude oil and natural gas condensate. By the end of 2019, the Company estimates that number of tank barges had declined to 335 inland tank barges and approximately five coastal tank barges transporting crude and natural gas condensate. During 2020, the COVID-19 pandemic and oil price volatility resulted in a sharp decrease in volumes of crude and natural gas condensate being transported. As of the end of 2021, approximately 160 to 170 inland tank barges and one coastal tank barge were transporting crude and natural gas condensate. As of the end of 2022, the Company estimates that approximately 170 to 200 inland tank barges were transporting crude and natural gas condensate. As of the end of 2023, the Company estimates that approximately 190 to 220 inland tank barges were transporting crude and natural gas condensate. Volatility in the price of natural gas and crude oil can also result in heightened uncertainty which may lead to decreased production and delays in new petrochemical and refinery plant construction. Increased competition for

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available black oil and petrochemical barge moves caused by reduced crude oil and natural gas condensate production could have an adverse impact on KMT including as a result of lower spot and term contract rates and/or reluctance to enter into or extend term contracts.

KMT could be adversely impacted by the construction of tank barges. At the present time, there are an estimated 4,007 inland tank barges in the United States, of which the Company operates 1,076, or 27%. For 2021, the Company estimated that industry-wide 70 new tank barges were placed in service, and 90 tank barges were retired. For 2022, the Company estimates that industry-wide 22 new tank barges were placed in service and retirements, net of reactivations, were flat. For 2023, the Company estimates that industry-wide 27 new tank barges were placed in service and 48 tank barges were retired. The Company estimates that approximately 25 to 30 new tank barges have currently been ordered for delivery in 2024 and expects a number of older tank barges will be retired, dependent on 2024 market conditions.

The long-term risk of an oversupply of inland tank barges may be mitigated by the fact that the inland tank barge industry has approximately 600 tank barges that are 30 years old or older and approximately 400 of those are 40 years old or older. Given the age profile of the industry inland tank barge fleet and extensive customer vetting standards, the expectation is that these older tank barges will continue to be removed from service and replaced by new tank barges as needed, with the extent of both retirements and new builds dependent on petrochemical and refinery production levels and crude oil and natural gas condensate movements, both of which can have a direct effect on industry-wide tank barge utilization, as well as term and spot contract rates.

Beginning in 2019, a decline in industry-wide demand for the movement of crude oil and natural gas condensate transportation volumes increased available capacity and resulted in some reluctance among certain customers to extend term contracts, which led to an increase in the number of coastal vessels operating in the spot market. In addition, the Company and the industry added new coastal tank barge capacity during 2019 through 2021. Much of this new capacity was replacement capacity for older vessels anticipated to be retired.

The Company estimates there are approximately 264 tank barges operating in the 195,000 barrels or less coastal industry fleet, the sector of the market in which the Company operates, and approximately 20 of those are over 25 years old. The Company is aware of one small specialized coastal ATB placed in service in 2021 and no ATBs placed in service in 2022 or 2023 with no further ATBs currently under construction.

Higher fuel prices could increase operating expenses and fuel price volatility could reduce profitability. The cost of fuel during 2023 was approximately 12% of marine transportation revenue. The Company’s marine transportation term contracts typically include fuel escalation clauses, or the customer pays for the fuel. However, there is generally a 30 to 120 day delay before contracts are adjusted depending on the specific contract. In general, the fuel escalation clauses are effective over the long-term in allowing the Company to adjust to changes in fuel costs due to fuel price changes; however, the short-term effectiveness of the fuel escalation clauses can be affected by a number of factors including, but not limited to, specific terms of the fuel escalation formulas, fuel price volatility, navigating conditions, tow sizes, trip routing, and the location of loading and discharge ports that may result in the Company over or under recovering its fuel costs. The Company’s spot contract rates generally reflect current fuel prices at the time the contract is signed but do not have escalators for fuel.

Significant increases in the construction cost of tank barges and towing vessels may limit the Company’s ability to earn an adequate return on its investment in new tank barges and towing vessels. The price of steel, economic conditions, and supply and demand dynamics can significantly impact the construction cost of new tank barges and towing vessels. Over the last 20 years, the Company’s average construction price for a new 30,000 barrel capacity inland tank barge has fluctuated up or down significantly. For example, the average construction price for a new 30,000 barrel capacity tank barge in 2009 was approximately 90% higher than in 2000, with increases primarily related to higher steel costs. During 2009, the United States and global recession negatively impacted demand levels for inland tank barges and as a result, the construction price of inland tank barges fell significantly in 2010, primarily due to a significant decrease in steel prices, as well as a decrease in the number of tank barges ordered. The cost of steel, a key material in barge construction, was relatively stable from 2010 through 2019. During 2020, at the onset of the COVID-19 pandemic, steel costs dropped, however, during 2021 and 2022, steel prices rose above 2019 levels due to supply chain disruptions before decreasing in 2023. Although steel prices decreased in 2023, they still remain near historical highs. These increases in steel costs and alterations in supply and demand dynamics, as well as higher labor costs, resulted in construction prices for a new 30,000 barrel tank barge increasing compared to prices in 2017 when there was an industry-wide over-capacity of inland tank barges in the market.

KMT could be adversely impacted by the failure of the Company’s shipyard vendors to deliver new vessels according to contractually agreed delivery schedules and terms. The Company contracts with shipyards to build new vessels and currently has vessels under construction. Construction projects are subject to risks of delay and cost overruns, resulting from shortages of equipment, materials and skilled labor; lack of shipyard availability; unforeseen design and engineering problems; work stoppages; weather interference; unanticipated cost increases; unscheduled delays in the delivery of material and equipment; and financial and other difficulties at shipyards including labor disputes, shipyard insolvency and inability to obtain necessary certifications and approvals. A significant delay in the construction of new vessels or a shipyard’s inability to perform under the construction contract could negatively impact the

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Company’s ability to fulfill contract commitments and to realize timely revenues with respect to vessels under construction. Significant cost overruns or delays for vessels under construction could also adversely affect the Company’s financial condition, results of operations and cash flows. The Company did not experience significant shipyard delays associated with the COVID-19 pandemic, including at its subsidiary, San Jac. The Company expects that its shipyard vendors, including San Jac, should be able to similarly manage their operations if an event of a similar impact were to occur in the future, but there is no guarantee that the vendors would be able to do so.

The Company is subject to competition in KMT. The inland and coastal tank barge industry remains very fragmented and competitive. The Company’s primary competitors are noncaptive inland tank barge operators and coastal operators. The Company also competes with companies who operate refined product and petrochemical pipelines, railroad tank cars and tractor-trailer tank trucks. Increased competition from any significant expansion of or additions to facilities or equipment by the Company’s competitors could have a negative impact on the Company’s results of operations. In addition, the Company’s failure to adhere to its safety, reliability and performance standards may impact its ability to retain current customers or attract new customers.

Distribution and Services Segment Risk Factors

KDS could be adversely impacted by future legislation, executive or other governmental orders, or additional regulation of oil and gas extraction, including hydraulic fracturing practices. The Company, through its United and S&S subsidiaries, is a distributor and service provider of engine and transmission related products for the oil and gas services, power generation and transportation industries, and a manufacturer of oilfield service equipment, including pressure pumping units. Various legislative and regulatory initiatives have been proposed that, if passed, could limit or discourage future production of oil and gas. Further, legislation may be enacted by Congress that would authorize the EPA to impose additional regulations on hydraulic fracturing. In addition, a number of states have adopted or are evaluating the adoption of legislation or regulations governing hydraulic fracturing or byproducts of the fracturing process. Related actions may also be taken via executive order. Federal or state legislation, executive or governmental orders, and/or regulations could materially impact customers’ operations and greatly reduce or eliminate demand for the Company’s pressure pumping fracturing equipment and related products. The Company is unable to predict whether future legislation or any other regulations will ultimately be enacted and, if so, the impact on KDS.

KDS could be adversely impacted by the construction of pressure pumping units by its competitors. During 2020, a significant reduction in oilfield activity as a result of oil price volatility and the COVID-19 pandemic resulted in a decrease to an estimated 6 million horsepower of pressure pumping units working in North America, with an estimated 1.5 million horsepower available to work, and 12 million horsepower stacked and in need of major repair. At the end of 2021, strong commodity prices resulted in an increase in horsepower demand with an estimated 12 million horsepower of pressure pumping units working in North America, with an estimated 8 million horsepower idled and in need of major repair. Supported by stronger commodity prices, surplus horsepower capacity declined as activity levels in North America improved during 2022 resulting in an increase to an estimated 15 million horsepower of pressure pumping units working in North America at the end of 2022, with an estimated 5 million horsepower idled and in need of major repair. Horsepower demand remained flat in 2023 with an estimated 15 million horsepower of pressure pumping units working in North America at the end of 2023, with an estimated 4 million horsepower idled and in need of major repair. Increased expansion of, or additions to, facilities or equipment by the Company’s competitors could have a negative impact on the Company’s results of operations.

Prevailing natural gas and crude oil prices, as well as the volatility of their prices, could have an adverse effect on KDS business. Lower energy prices generally result in a decrease in the number of oil and gas wells being drilled. Oilfield service companies reduce their capital spending, resulting in decreased demand for new parts and equipment, including pressure pumping units, provided by KDS. This may also lead to order cancellations from customers or customers requesting to delay delivery of new equipment. The Company also services offshore supply vessels and offshore drillings rigs operating in the Gulf of Mexico, as well as internationally. Low energy prices may negatively impact the number of wells drilled in the Gulf of Mexico and international waters. Prolonged downturns in oil and gas prices may cause substantial declines in oilfield service and exploration expenditures and could adversely impact oil and gas manufacturing, remanufacturing, parts and distribution business. In addition, energy price volatility may also result in difficulties in the Company’s ability to address variations in production on a timely basis and, therefore, could result in an adverse impact on KDS.

The Company is subject to competition in KDS. The distribution and services industry is very competitive. The segment’s oil and gas market’s principal competitors are independent distribution and service and oilfield manufacturing companies and other factory-authorized distributors and service centers. In addition, certain oilfield service companies that are customers of the Company also manufacture and service a portion of their own oilfield equipment. Increased competition in the distribution and services industry and continued low price of natural gas, crude oil or natural gas condensate, and resulting decline in drilling for such natural resources in North American shale formations, could result in less oilfield equipment being manufactured and remanufactured, lower rates for service and parts pricing and result in less manufacturing, remanufacturing, service and repair opportunities and parts sales for the Company. For the commercial and industrial market, the segment’s primary marine diesel competitors are independent diesel services companies and other factory-authorized distributors, authorized service centers and authorized marine dealers. Certain operators of diesel powered marine equipment also elect to maintain in-house service capabilities. For power generation, the primary competitors are other independent service companies.

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Loss of a distributorship or other significant business relationship or disruptions of supply could adversely affect KDS. KDS has had a relationship with EMD, the largest manufacturer of medium-speed diesel engines, since the 1960s. The Company, through Kirby Engine Systems, serves as an EMD distributor for select markets and locations for both service and parts. With the acquisition of S&S in September 2017, the Company added additional EMD distributorship rights in key states, primarily through the Central and South areas of the United States. With the S&S acquisition, the Company became the United States distributor for EMD marine and power generation applications. Sales and service of EMD products account for approximately 3% of the Company’s revenues for 2023. Although the Company considers its relationship with EMD to be strong, the loss of the EMD distributorship and service rights, or a disruption of the supply of EMD parts, could have a negative impact on the Company’s ability to service its customers. In 2020, with the acquisition of Convoy Servicing Company and Agility Fleet Services, LLC, the Company expanded its dealership network of Thermo King refrigeration systems for trucks, railroad cars, and other land transportation markets in Texas and Colorado. In 2023, sales and service of Thermo King products comprised approximately 5% of the Company’s revenues.

United and S&S have maintained continuous exclusive distribution rights for MTU and Allison since the 1940s. United and S&S are two of MTU’s top five distributors of off-highway engines in North America, with exclusive distribution rights in multiple states. In addition, as distributors of Allison products, United and S&S have exclusive distribution rights in multiple key growth states. United and S&S are also the distributors for parts, service and warranty on Daimler truck engines and related equipment in multiple states. Sales and service of MTU, Allison, and Daimler products accounted for approximately 13% of the Company’s revenues during 2023. Although the Company considers its relationships with MTU, Allison, and Daimler to be strong, the loss of MTU, Allison, or Daimler distributorships and service rights, or a disruption of the supply of MTU or Allison parts, could have a negative impact on the Company’s ability to service its customers.

In addition to its relationships with MTU, Allison, and Daimler, the Company also has relationships with many other distributors and parts suppliers and the loss of a distributorship and service rights, or a disruption of the supply of parts from any of these other distributors or part suppliers could also have a negative impact on the Company’s ability to service its customers.

General Corporate Risk Factors

The Company is subject to adverse weather conditions in KMT and KDS. KMT is subject to weather condition volatility. Physical impacts of climate change could have a material adverse effect on the Company's costs and operations. There has been public discussion that climate change may be associated with rising sea levels as well as extreme weather conditions such as more intense hurricanes, thunderstorms, tornadoes, drought, and snow or ice storms. Extreme weather conditions may increase the Company’s costs or cause damage to its facilities, and any damage resulting from extreme weather may not be fully insured. Many of the Company’s facilities are located near coastal areas or waterways where rising sea levels or flooding could disrupt the Company’s operations or adversely impact its facilities. Adverse weather conditions such as high or low water on the inland waterway systems, fog and ice, tropical storms, hurricanes, and tsunamis on both the inland waterway systems and throughout the United States coastal waters can impair the operating efficiencies of the marine fleet. Such adverse weather conditions can cause a delay, diversion or postponement of shipments of products and are totally beyond the control of the Company. Tropical storms and hurricanes may also impact the Company’s customers resulting in reduced demand for the Company’s services. In addition, adverse water and weather conditions can negatively affect a towing vessel’s performance, tow size, loading drafts, fleet efficiency, limit navigation periods and dictate horsepower requirements. KDS is also subject to tropical storms and hurricanes impacting its coastal locations and those of its customers as well as tornados impacting its Oklahoma facilities. The risk of flooding as a result of hurricanes and tropical storms as well as other weather events may impede travel via roadways, suspend service work, and impact deliveries and the Company’s ability to fulfill orders or provide services in KDS.

The Company may be unable to make attractive acquisitions or successfully integrate acquired businesses, and any inability to do so may adversely affect the Company’s business and hinder its ability to grow. The Company has made asset and business acquisitions in the past and may continue to make acquisitions of assets or businesses in the future that complement or expand the Company’s current business. The Company may not be able to identify attractive acquisition opportunities. Even if attractive acquisition opportunities are identified, the Company may not be able to complete the acquisition or do so on commercially acceptable terms. The success of any completed acquisition depends on the Company’s ability to integrate the acquired assets or business effectively into the Company’s existing operations. The process of integrating acquired assets or businesses may involve difficulties that require a disproportionate amount of the Company’s managerial and financial resources to resolve. The value of acquired assets or businesses may be negatively impacted by a variety of circumstances unknown to the Company prior to the acquisition. In addition, possible future acquisitions may be larger and for purchase prices significantly higher than those paid for earlier acquisitions. No assurance can be given that the Company will be able to identify additional suitable acquisition opportunities, negotiate acceptable terms, obtain financing for acquisitions on acceptable terms or successfully acquire identified targets. The Company’s failure to achieve synergies, to successfully integrate the acquired businesses and assets into the Company’s existing operations, or to minimize any unforeseen operational difficulties could have a material adverse effect on the Company’s business, financial condition, and results of operations. In addition, agreements governing the Company’s indebtedness from time to time may impose certain limitations on the Company’s ability to undertake acquisitions or make investments or may limit the Company’s ability to incur certain indebtedness and liens, which could limit the Company’s ability to make acquisitions.

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The Company’s failure to comply with the FCPA, or similar local applicable anti-bribery laws, could have a negative impact on its ongoing operations. The Company’s operations outside the United States require the Company to comply with both United States and international regulations. For example, in addition to any similar applicable local anti-bribery laws, the Company's operations in countries outside the United States are subject to the FCPA, which prohibits United States companies or their employees and third party representatives from providing anything of value to a foreign official for the purposes of influencing any act or decision of these individuals in their official capacity to help obtain or retain business, direct business to any person or corporate entity, or obtain any unfair advantage. The Company has internal control policies and procedures and has implemented training and compliance programs for its employees and third party representatives with respect to the FCPA. However, the Company’s policies, procedures and programs may not always protect it from reckless or criminal acts committed by its employees or third party representatives, and severe criminal or civil sanctions could be the result of violations of the FCPA or any other applicable anti-bribery law in countries where the Company does business. The Company is also subject to the risks that its employees, joint venture partners, and third party representatives outside of the United States may fail to comply with other applicable laws.

The Company is subject to risks associated with possible climate change legislation, regulation and international accords. Greenhouse gas emissions, including carbon emissions or energy use, have increasingly become the subject of a large amount of international, national, regional, state and local attention. International agreements and national, regional, and state legislation and regulatory measures that aim to directly or indirectly limit or reduce greenhouse gas emissions are in various stages of implementation.

The United States Congress has considered, but has not passed, various bills that would create an economy-wide “cap-and-trade” system that would establish a limit (or cap) on overall greenhouse gas emissions and create a market for the purchase and sale of emissions permits or “allowances.” Any proposed cap-and-trade legislation would likely affect the chemical industry due to anticipated increases in energy costs as fuel providers pass on the cost of the emissions allowances, which they would be required to obtain under cap-and-trade to cover the emissions from fuel production and the eventual use of fuel by the Company or its energy suppliers. In addition, cap-and-trade proposals would likely increase the cost of energy, including purchases of diesel fuel, steam and electricity, and certain raw materials used or transported by the Company. Proposed domestic and international cap-and-trade systems could materially increase raw material and operating costs of the Company’s customer base. Future environmental regulatory developments related to climate change in the United States that restrict emissions of greenhouse gases could result in financial impacts on the Company’s operations that cannot be predicted with certainty at this time.

In addition, current global trends incorporating carbon neutral policies and reduction in greenhouse gas emissions are driving decarbonization initiatives across all industries to mitigate the impact on climate change and may result in a decline in global and U.S. hydrocarbon usage. Such a decline in hydrocarbon usage (for example, as a result of an increase in electric vehicles) could result in a reduction in demand for (a) the Company’s services in KMT to the extent there is reduced demand for crude oil and other feedstocks used and the products produced by the Company’s major refining customers and (b) for the Company’s products and services in KDS to the extent there is reduced demand in the exploration and production of hydrocarbons by the Company’s oil and gas customers.

Loss of a large customer could adversely affect the Company. Five KMT customers accounted for approximately 16% of the Company’s 2023 revenue, and 17% of 2022 and 2021 revenue. The Company has contracts with these customers expiring in 2024 through 2026. Three KDS customers accounted for approximately 12% of the Company’s 2023 revenue, 9% of 2022 revenue, and 6% of 2021 revenue. Although the Company considers its relationships with these companies to be strong, the loss of any of these customers, or their inability to meet financial obligations, could have an adverse effect on the Company.

The Company relies on critical operating assets including information systems for the operation of its businesses, and the failure of such assets or any critical information system, including as a result of natural disasters, terrorist acts, a cybersecurity attack, or other extraordinary events, may adversely impact its businesses. The Company is dependent on its critical operating assets and technology infrastructure and must maintain and rely upon critical information systems and security of its assets for the effective and safe operation of its businesses. These assets include vessels, vessel equipment, property and facilities, as well as information systems, such as software applications, hardware equipment, and data networks and telecommunications.

The Company’s critical assets and information systems, including the Company’s proprietary vessel management computer system, are subject to damage or interruption from a number of potential sources, including but not limited to, natural disasters, terrorist acts, cybersecurity attacks, software viruses, and power failures. In addition to standard safety operating procedures, the Company has implemented measures such as business continuity plans, hurricane preparedness plans, emergency recovery processes, and security preparedness plans to protect physical assets and to recover from damage to such assets. The Company has also implemented virus protection software, intrusion detection systems and annual attack and penetration audits to protect information systems to mitigate these risks. However, the Company cannot guarantee that its critical assets or information systems cannot be damaged or compromised.

Any damage or compromise of its critical assets or data security or its inability to use or access these critical assets and information systems could adversely impact the efficient and safe operation of its businesses, or result in the failure to safely operate its equipment, and maintain the confidentiality of data of its customers or its employees and could subject the Company to increased operating expenses

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or legal action, which could have an adverse effect on the Company. Although to date the Company is unaware of any material data breach or system disruption, including a cyber-attack, the Company cannot provide any assurances that such events and impacts will not be material in the future. The Company’s efforts to deter, identify, mitigate and/or eliminate future breaches may require significant additional effort and expense and may not be successful.

Limitations on the Company’s ability to obtain, maintain, protect, or enforce its proprietary information and any successful intellectual property challenges or infringement proceedings, including its trade secrets could affect the Company's competitive position. The Company’s distribution and services businesses rely on a variety of intellectual property rights for its product and services. The Company’s intellectual property could be adversely affected by successful intellectual property challenges or infringement proceedings against it which could materially and adversely affect its competitive position. The Company may also be adversely affected when its patents are unenforceable, where claims allowed are not sufficient to protect its technology or its trade secrets are not adequately protected. The Company's failure to protect its proprietary information and any successful challenges to the Company's intellectual property rights could have an adverse effect on the Company.

A deterioration of the Company’s credit profile, disruptions of the credit markets or higher interest rates could restrict its ability to access the debt capital markets or increase the cost of debt. Deterioration in the Company’s credit profile may have an adverse effect on the Company’s ability to access the private or public debt markets and also may increase its borrowing costs. If the Company’s credit profile deteriorates significantly its access to the debt capital markets or its ability to renew its committed lines of credit may become restricted, its cost of debt may increase, or the Company may not be able to refinance debt at the same levels or on the same terms. Because the Company relies on its ability to draw on its Revolving Credit Facility to support its operations as needed, any volatility in the credit and financial markets that prevents the Company from accessing funds on acceptable terms could have an adverse effect on the Company’s financial condition and cash flows. Additionally, the pricing grids on Company’s Revolving Credit Facility and Term Loan contain a ratings grid that includes a possible increase in borrowing rates if the Company’s rating declines. Furthermore, the Company incurs interest under its Revolving Credit Facility based on floating rates. Floating rate debt creates higher debt service requirements if market interest rates increase, which would adversely affect the Company’s cash flow and results of operations.

Corporate responsibility, specifically related to ESG matters, may impose additional costs and expose the Company to new risks. There is an increasing focus from regulators, certain investors, and other stakeholders concerning environmental, social, and governance (“ESG”) matters, both in the United States and internationally. The Company communicates certain ESG-related initiatives, goals, and/or aspirations regarding environmental matters, diversity, responsible sourcing and social investments, and other matters in its annual Sustainability Report, on its website, in its filings with the SEC, and elsewhere. These initiatives, goals, or aspirations reflect the Company’s current plans and are not guarantees that the Company will be able to achieve them. The standards for tracking and reporting on ESG matters are relatively new, have not been harmonized and continue to evolve. Further, the statutory and regulatory requirements continue to evolve as well. In 2023, the State of California enacted climate related legislation and the SEC is expected to issue its own climate disclosure rules in 2024, both of which will or are expected to impose additional reporting requirements on the Company resulting in additional compliance cost and expense. The Company’s selection of disclosure frameworks that seek to align with various reporting standards may change from time to time and may result in a lack of comparative data from period to period. The ESG-related initiatives, goals and/or aspirations could be difficult to achieve and costly to implement, and the Company may be unable to economically develop or deploy technologies to achieve its goals or aspirations, if at all. In addition, the Company could be criticized for the timing, scope or nature of these initiatives, goals, or aspirations, or for any revisions to them. As mandatory and voluntary disclosures about ESG matters increase, the Company could be penalized or criticized for the accuracy, adequacy, or completeness of such disclosures. The Company’s actual or perceived failure to report accurately or achieve its ESG-related initiatives, goals, or aspirations could result in government enforcement action, negatively impact its reputation, result in ESG-focused investors not purchasing and holding Company stock, or otherwise materially harm the Company’s business.

Increased prices and inflation could negatively impact the Company’s margin performance and financial results. Increased inflation, including rising prices for items, such as raw materials, fuel, parts and components, freight, packaging, supplies, labor and energy increases the Company’s costs to provide services and manufacture and distribute the Company’s products. The Company does not currently use financial derivatives to hedge against volatility in commodity prices. The Company uses market prices for materials, fuel, parts and components. The Company may be unable to pass these rising costs on to its customers. To mitigate this exposure, the Company attempts to include cost escalation clauses in its longer-term marine transportation contracts whereby certain costs, including fuel, can largely be passed through to its customers. In KDS, the cost of major components for large manufacturing orders is secured with suppliers at the time a customer order is finalized, which limits exposure to cost escalations. Results of operations and margin performance can be negatively affected if the Company is unable to mitigate the impact of these cost increases through contractual means and is unable to increase prices to sufficiently offset the effect of these cost increases.

The Company could be adversely impacted by materials shortages, delays, and disruptions in supply chain. Materials, components, and equipment essential to the Company’s operations, such as original equipment manufacturer engines, transmissions, generators, electrical components and steel, are normally readily available, but shortages as a result of supply chain disruptions can adversely impact the Company’s operations, particularly where the Company has a relationship with a single supplier for a particular resource. Many of

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the items essential to the Company’s business require the use of shipping services to transport them to the Company’s facilities. Shipping delays or disruptions may result in operational slowdowns, especially where materials, components, or equipment are necessary to complete a project or order for the Company’s customers, particularly in the manufacturing business of KDS. These constraints could have a material adverse effect on the Company and contribute to increased buildup of inventories. In addition, price increases imposed by the Company’s vendors for materials and shipping services used in its business, and the inability to pass these increases through to its customers, could have a material adverse effect on the Company.

Continuing impacts resulting from actual or threatened health epidemics, and pandemics or other major health crisis could materially and adversely affect the Company’s business, financial condition and results of operations. The Company’s business could be impacted adversely by the effects of public health epidemics, pandemics or other major heath crises (which we refer to collectively as public health crises). Actual or threatened public health crises may have a number of adverse impacts, including volatility in the global economy, impacts to the Company’s customers’ business operations, or significant disruptions in waterborne transportation of cargoes, and supply chain activity, caused by a variety of factors such as quarantines, supplier factory and office closures, or other government-imposed restrictions, any of which could adversely impact the Company’s business, financial condition, and results of operations. In response to the COVID-19 pandemic, various countries, including the United States, either mandated or recommended business closures, travel restrictions or limitations, social distancing, and/or self-quarantine, among other restrictions. Additionally, various state and local governments in locations where the Company operates took similar actions. Governments removed, eased, reinstated, or implemented new protocols or restrictions in response to reassessment of the risk of COVID-19, based in part on, changing levels of infection and hospitalization rates. There has been and continues to be a negative impact on the global and United States economies and supply chains, including the oil and gas industry, which has created delays and reduced demand for the Company’s products and services and in some cases, resulted in delays in performance of its contracts with customers.

The Company is unable to predict the extent to which major health crisis or other public health threats that may arise in the future may affect the global and United States economies and supply chain, which could have a material impact on its business. The degree to which any future disease outbreaks or public health threats may impact the Company’s revenues, results of operations and financial condition is uncertain and will depend on future developments. The impact of epidemics or COVID-19 and other pandemics may also exacerbate other risks discussed above, any of which could have a material effect on the Company.

Item 1B. Unresolved Staff Comments

Not applicable.

Item 1C. Cybersecurity

The Company is committed to maintaining robust governance and oversight of cybersecurity risks and to implementing processes, controls and technologies designed to help assess, identify, and manage material risks. The Company’s Board of Directors has ultimate oversight of cybersecurity risks, which it manages as part of the Company’ enterprise risk management program. The Audit Committee assists the Board in reviewing the Company’s information security programs, including review of cybersecurity processes, procedures and safeguards. To more effectively prevent, detect and respond to information security threats, the Company maintains a cyber risk management program, which is supervised by a Company executive officer, the Vice President and Chief Information Officer, whose team is responsible for leading company-wide cybersecurity strategy, policy, standards, architecture and processes. The Vice President and Chief Information Officer has extensive experience assessing and managing cybersecurity programs and risks and has served in this position since 2019. The team includes the Senior Director of IT Operations & Security with a certification in information security, who reports directly to the Vice President and Chief Information Officer. The Audit Committee receives regular reports from the Vice President and Chief Information Officer on, among other things, the Company’s cyber risks and threats, the status of projects to strengthen the Company’s information security systems, assessments of the Company’s security program and the emerging threat landscape. Additionally, the Vice President and Chief Information Officer chairs the Cybersecurity Risk Oversight working group, which drives awareness, ownership and alignment across broad governance and risk stakeholder groups for effective cybersecurity risk management and reporting. Upon the occurrence of a cybersecurity incident, a documented process is followed to escalate notifications to the Company’s CEO and Board, as appropriate.

The Company annually engages third parties such as assessors, consultants and auditors (as well as its internal audit department) to audit the Company’s information security programs, whose findings are reported to the Audit Committee. The Company also actively engage with key vendors, industry participants, and the U.S. Coast Guard as part of its efforts, which are reported to the Audit Committee.

The Company’s approach to cybersecurity risk management includes the following key elements:

•Continuous monitoring – The Company actively searches for cybersecurity threats, including those associated with its use of third party vendors, through the use of data analytics and network monitoring systems.

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•Third party risk assessments – From time to time, the Company engages third party consultants or other advisors to assist in assessing points of vulnerability in its information security systems.

•Internal threats – The Company maintains a program designed to monitor and address risk from within the Company.

•Vendor engagement – The Company assesses the risk of vendors who are critical digital partners in order to support the resiliency of the supply chain and seeks to include risk appropriate terms and conditions in its vendor contracts.

•Training and Awareness – The Company has various information technology policies, including an Information Security Awareness Training Policy, that relate to cybersecurity. The Company provides employee training that reinforces its information technology policies, standards and practices, as well as the expectation that employees comply with these policies. This training empowers employees to identify and report potential cybersecurity risks and protect the Company’s resources and information. This training is mandatory for all employees globally and is administered on a periodic basis, and it is supplemented by Company-wide testing initiatives, including periodic phishing tests. The Company provides specialized security training for certain employee roles. The Company also requires employees to sign confidentiality agreements, where appropriate to their role.

The Company continues to invest in its cybersecurity systems and to enhance its internal controls and processes. While the Company has not, as of the date of this Form 10-K, experienced a cybersecurity threat or incident that resulted in a material adverse impact to its business or operations, there can be no guarantee that the Company will not experience such an incident in the future. For more information regarding the risks the Company faces from cybersecurity threats, please see Item 1A-Risk Factors.

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Item 2. Properties

The principal offices of the Company are located in Houston, Texas. The Company believes that its facilities are adequate for its needs and additional facilities would be available if required. The Company’s significant operating facilities include the following locations:

Location	Building(s) Size (Approximate Square Feet)	Owned or Leased	Activity
KMT
Baton Rouge, Louisiana	19,300	Leased	Operations and fleeting
Channelview, Texas	108,300	Owned	Operations, fleeting, shipyard, training and cleaning
Corpus Christi, Texas	3,600	Leased	Operations
Freeport, Texas	6,500	Leased	Fueling and fleeting
Houston, Texas	73,000	Owned	KMT, KDS and Corporate Headquarters
Lake Charles, Louisiana	500	Leased	Fleeting
Miami, Florida	8,500	Leased	Operations and dockage
Port Arthur, Texas	1,000	Leased	Fleeting
Seattle, Washington	10,200	Leased	Operations and inventory
Staten Island, New York	7,800	Leased	Operations, inventory and dockage
Westwego, Louisiana	15,300	Owned	Operations
KDS
Albany, New York	40,000	Leased	Service and repairs
Austin, Texas	1,500	Leased	Service and repairs
Baton Rouge, Louisiana	23,500	Leased	Service and repairs
Belle Chasse, Louisiana	34,700	Owned	Service and repairs
Chesapeake, Virginia	30,000	Leased	Service and repairs
Commerce City, Colorado	151,600	Owned	Service and repairs
Corpus Christi, Texas	44,100	Owned	Service and repairs
Dallas, Texas	211,100	Owned	Service and repairs
El Paso, Texas	9,000	Leased	Service and repairs
Fort Lauderdale, Florida	40,400	Leased	Service and repairs
Fort Myers, Florida	9,900	Owned	Service and repairs
Fort Pierce, Florida	10,300	Owned	Service and repairs
Fort Worth, Texas	22,600	Owned	Service and repairs
Houma, Louisiana	109,700	Owned	Service and repairs
Houston, Texas	491,100	Owned	Manufacturing, service and repairs
Jacksonville, Florida	44,800	Leased	Service and repairs
Laredo, Texas	7,000	Leased	Service and repairs
Little Rock, Arkansas	21,500	Owned	Service and repairs
Lodi, New Jersey	57,300	Leased	Service and repairs
Longview, Texas	50,000	Owned	Service and repairs
Lubbock, Texas	27,500	Owned	Service and repairs
Marlborough, Massachusetts	45,700	Leased	Service and repairs
Miami, Florida	54,400	Leased	Service and repairs
Middletown, Connecticut	38,800	Leased	Service and repairs
Mobile, Alabama	27,000	Owned	Service and repairs
Mount Pleasant, Texas	3,100	Leased	Service and repairs
New Iberia, Louisiana	33,000	Owned	Service and repairs
Ocala, Florida	15,200	Owned	Service and repairs
Odessa, Texas	49,500	Owned	Service and repairs
Oklahoma City, Oklahoma	446,400	Owned/Leased	Manufacturing, service and repairs
Orlando, Florida	44,600	Leased	Service and repairs
Paducah, Kentucky	73,700	Owned/Leased	Service and repairs
Panama City, Florida	10,200	Owned	Service and repairs
Pharr, Texas	59,300	Leased	Service and repairs
Piscataway, New Jersey	39,900	Leased	Service and repairs
Rocky Mount, North Carolina	50,000	Leased	Service and repairs
San Antonio, Texas	42,100	Owned	Service and repairs
Seattle, Washington	19,500	Leased	Service and repairs
Shreveport, Louisiana	50,000	Owned	Service and repairs
Tampa, Florida	50,900	Owned	Service and repairs
Thorofare, New Jersey	24,200	Leased	Service and repairs
Tulsa, Oklahoma	37,600	Leased	Service and repairs
West Palm Beach, Florida	7,000	Leased	Service and repairs
Wichita Falls, Texas	11,500	Leased	Service and repairs

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Item 3. Legal Proceedings

See Note 14, Contingencies and Commitments to the Company’s financial statements.

Item 4. Mine Safety Disclosures

Not applicable.

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PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

The Company’s common stock is traded on the New York Stock Exchange under the symbol KEX. Additional market information for this item is incorporated by reference to the annual report to be provided to the Company’s stockholders pursuant to Rule 14a-3(b).

As of February 16, 2024, the Company had 58,522,000 outstanding shares held by approximately 370 stockholders of record; however, the Company believes the number of beneficial owners of common stock exceeds this number. Information for this item relating to equity compensation plans is incorporated by reference to the definitive proxy statement to be filed by the Company with the Commission pursuant to Regulation 14A within 120 days of the close of the fiscal year ended December 31, 2023. See also Note 8, Stock Award Plans to the Company’s financial statements for additional information.

The Company does not have an established dividend policy. Decisions regarding the payment of future dividends will be made by the Board of Directors based on the facts and circumstances that exist at that time. Since 1989, the Company has not paid any dividends on its common stock. The Company’s credit agreements contain covenants restricting the payment of dividends by the Company at any time when there is a default under the agreements.

The following table is a summary of purchases of the Company's common stock during the 2023 fourth quarter.

Period	Total Number of Shares Purchased	Average Price Paid Per Share	Total Number of Shares Purchased as Part of Publicly Announced Plans	Maximum Number of Shares that May Yet be Purchased Under the Plans
October 1 — October 31, 2023	131,603	$ 81.16	—	—
November 1 — November 30, 2023	294,843	$ 76.46	—	—
December 1 — December 31, 2023	246,833	$ 75.63	—	—
Total	673,279	$ 77.08	—	—

Purchases of the Company's common stock during the 2023 fourth quarter were made in the open market pursuant to a discretionary authorization by the Board of Directors.

Item 6. Reserved

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Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Statements contained in this Form 10-K that are not historical facts, including, but not limited to, any projections contained herein, are forward-looking statements and involve a number of risks and uncertainties. Such statements involve risks and uncertainties. Such statements can be identified by the use of forward-looking terminology such as “may,” “will,” “expect,” “anticipate,” “estimate,” or “continue,” or the negative thereof or other variations thereon or comparable terminology. The actual results of the future events described in such forward-looking statements in this Form 10-K could differ materially from those stated in such forward-looking statements. Among the factors that could cause actual results to differ materially are: adverse economic conditions, industry competition and other competitive factors, adverse weather conditions such as high water, low water, tropical storms, hurricanes, tsunamis, fog and ice, tornados, COVID-19 or other pandemics, marine accidents, lock delays, fuel costs, interest rates, construction of new equipment, government and environmental laws and regulations, and the timing, magnitude and number of acquisitions made by the Company. For a more detailed discussion of factors that could cause actual results to differ from those presented in forward-looking statements, see Item 1A-Risk Factors. Forward-looking statements are based on currently available information and the Company assumes no obligation to update any such statements.

For purposes of Management’s Discussion, all net earnings per share attributable to Kirby common stockholders are “diluted earnings (loss) per share.” The weighted average number of common shares outstanding applicable to diluted earnings (loss) per share for 2023, 2022, and 2021 were 59,857,000, 60,329,000, and 60,053,000, respectively. Refer to the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 for management's discussion and analysis of financial condition and results of operations for 2022 compared to 2021.

Overview

The Company is the nation’s largest domestic tank barge operator, transporting bulk liquid products throughout the Mississippi River System, on the Gulf Intracoastal Waterway, and coastwise along all three United States coasts. The Company transports petrochemicals, black oil, refined petroleum products and agricultural chemicals by tank barge. Through KDS, the Company provides after-market service and parts for engines, transmissions, reduction gears, and related equipment used in oilfield services, marine, power generation, on-highway, and other industrial applications. The Company also rents equipment including generators, industrial compressors, and high capacity lift trucks, and refrigeration trailers for use in a variety of industrial markets, and manufactures and remanufactures oilfield service equipment, including pressure pumping units, manufactures cementing and pumping equipment as well as coil tubing and well intervention equipment, electric power generation equipment, specialized electrical distribution and control equipment, and high capacity energy storage/battery systems for oilfield service and railroad customers.

The following table summarizes key operating results of the Company (in thousands, except per share amounts):

	Year Ended December 31,
	2023		2022		2021
Total revenues	$	3,091,640	$	2,784,754	$	2,246,660
Net earnings (loss) attributable to Kirby	$	222,935	$	122,291	$	(246,954	)
Net earnings (loss) per share attributable to Kirby common stockholders – diluted	$	3.72	$	2.03	$	(4.11	)
Net cash provided by operating activities	$	540,228	$	294,128	$	321,576
Capital expenditures	$	401,730	$	172,606	$	98,015

The 2023 first quarter included $3.0 million before taxes, $2.4 million after taxes, or $0.04 per share of costs related to the strategic review and shareholder engagement and $2.7 million before taxes, $2.2 million after taxes, or $0.04 per share of other income associated with the interest on a refund from the Internal Revenue Service (“IRS”).

The 2022 fourth quarter included $3.3 million before taxes, $2.4 million after taxes, or $0.04 per share of severance expense. The 2022 fourth quarter also included $0.9 million before taxes, $0.6 million after taxes, or $0.01 per share of professional fees related to the Company’s strategic alternatives review. The 2022 second quarter included $1.5 million before taxes, $1.3 million after taxes, or $0.02 per share of severance expense.

The 2021 third quarter included $340.7 million before taxes, $275.1 million after taxes, or $4.58 per share, non-cash charges related to impairment of long-lived assets related to coastal marine transportation equipment and impairment of goodwill in KMT. See Note 7, Impairments and Other Charges in the financial statements for additional information. The 2021 fourth quarter was also impacted by a one-time deferred tax provision of $5.7 million or $0.09 per share related to a change in Louisiana tax law. See Note 9, Taxes on Income for additional information.

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Cash provided by operating activities in 2023 increased compared to 2022 primarily due to higher business activity levels and the receipt of an IRS refund of $70.4 million plus accrued interest. During 2023, capital expenditures of $401.7 million included $255.4 million in KMT and $146.3 million in KDS and corporate, more fully described under cash flow and capital expenditures below.

The Company projects net cash flow from operations in 2024 of between $600 million and $700 million and expects capital expenditures to range between $290 million and $330 million. The Company received grants from various government entities totaling approximately $3.7 million in 2023 related to certain emission reduction projects and has applied for and been awarded grants totaling approximately $4 million which it expects to receive reimbursements for in late 2024 and 2025.

The Company’s debt-to-capitalization ratio decreased to 24.2% at December 31, 2023 from 26.2% at December 31, 2022, primarily due an increase in total equity, primarily from net earnings attributable to Kirby of $222.9 million during 2023 and a reduction of debt outstanding of $63.0 million, partially offset by treasury stock purchases of $112.8 million. The Company’s debt outstanding as of December 31, 2023 and December 31, 2022 is detailed in Long-Term Financing below.

Marine Transportation

The following table summarizes the Company’s marine transportation fleet:

	December 31,
	2023		2022
Inland tank barges:
Owned		1,043		999
Leased		33		38
Total		1,076		1,037
Barrel capacity (in millions)		23.7		23.1
Active inland towboats (quarter average):
Owned		214		216
Chartered		67		61
Total		281		277
Coastal tank barges:
Owned		28		28
Leased		—		1
Total		28		29
Barrel capacity (in millions)		2.9		3.0
Coastal tugboats:
Owned		24		24
Chartered		1		3
Total		25		27
Offshore dry-bulk cargo barges (owned)		4		4
Offshore tugboats and docking tugboat (owned and chartered)		5		5

The Company also owns shifting operations and fleeting facilities for dry cargo barges and tank barges on the Houston Ship Channel and in Freeport and Port Arthur, Texas, and Lake Charles, Louisiana, and its San Jac shipyard for building towboats and performing routine maintenance near the Houston Ship Channel, as well as a two-thirds interest in Osprey Line, L.L.C., which transports project cargoes and cargo containers by barge.

For 2023, 56% of the Company’s revenues were generated by KMT. The segment’s customers include many of the major petrochemical and refining companies that operate in the United States. Products transported include intermediate materials used to produce many of the end products used widely by businesses and consumers — plastics, fibers, paints, detergents, oil additives and paper, among others, as well as residual fuel oil, ship bunkers, asphalt, gasoline, diesel fuel, heating oil, crude oil, natural gas condensate and agricultural chemicals. Consequently, the Company’s marine transportation business is directly affected by the volumes produced by the Company’s petroleum, petrochemical and refining customer base.

KMT’s revenues for 2023 increased 6% compared to 2022 and operating income increased 75%, compared to 2022. The increases for 2023 were primarily due to improved term and spot pricing and utilization in the inland market when compared to 2022. This was partially offset by various lock closures along the Gulf Intracoastal Waterway and Illinois River, resulting in higher delay days. In

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addition, several refinery outages also impacted utilization. Revenues and operating income in 2022 were impacted by record low water levels on the Mississippi River during the 2022 fourth quarter. Also, the 2022 first quarter was impacted by the COVID-19 Omicron variant as increased cases of the virus among the Company’s mariners led to crewing challenges, lost revenue and increased operating costs. For 2023 and 2022, the inland tank barge fleet contributed 82% and 79%, respectively, and the coastal fleet contributed 18% and 21%, respectively, of marine transportation revenues.

Overall inland tank barge utilization levels improved in 2023 as compared to 2022, ranging from the low to mid-90% range during the 2023 first quarter, the low 90% range during the 2023 second quarter, the high 80% range during the 2023 third quarter, and the low 90% range in the 2023 fourth quarter. During 2022, inland tank barge utilization levels ranged from the mid-80% range during the 2022 first quarter, the low 90% range during both the 2022 second and third quarters, and the low 90% range in the 2022 fourth quarter. Utilization in the 2023 fourth quarter improved from the 2023 third quarter, which was negatively impacted by Illinois River lock closures and several refinery outages.

Coastal tank barge utilization levels during 2023 averaged in the mid to high 90% range during both the 2023 first and second quarters, the mid-90% range during the 2023 third quarter and the low to mid-90% range during the 2023 fourth quarter. For 2022, coastal tank barge utilization levels averaged in the low 90% range during both the 2022 first and second quarters and low to mid-90% range during both the 2022 third and fourth quarters.

Approximately 60% of the inland marine transportation revenues were under term contracts and 40% were under spot contracts in 2023 and 2022. Term contracts provide the operations with a reasonably predictable revenue stream. Inland time charters, which insulate the Company from revenue fluctuations caused by weather and navigational delays and temporary market declines, represented 63% of the inland revenues under term contracts during 2023 and 58% in 2022. During 2023 and 2022, approximately 85% and 75%, respectively, of coastal revenues were under term contracts and 15% and 25%, respectively, were under spot contracts. Coastal time charters represented approximately 90% of coastal revenues under term contracts during both 2023 and 2022. Term contracts have contract terms of 12 months or longer, while spot contracts have contract terms of less than 12 months.

The following table summarizes the average range of pricing changes in term and spot contracts renewed during 2023 compared to contracts renewed during the corresponding quarter of 2022:

	Three Months Ended
	March 31, 2023	June 30, 2023	September 30, 2023	December 31, 2023
Inland market:
Term increase	10% – 12%	10% – 12%	7% – 9%	7% – 9%
Spot increase	23% – 26%	26% – 29%	14% – 16%	15% – 18%
Coastal market (a):
Term increase	10% – 12%	16% – 18%	10% – 12%	20% – 22%
Spot increase	20% – 23%	25% – 28%	31% – 33%	34% – 36%

(a)Spot and term contract pricing in the coastal market are contingent on various factors including geographic location, vessel capacity, vessel type, and product serviced.

Effective January 1, 2023, annual escalators for labor and the producer price index on a number of inland multi-year contracts resulted in rate increases on those contracts of approximately 9%, excluding fuel.

The 2023 marine transportation operating margin was 13.9% compared to 8.4% for 2022.

Distribution and Services

The Company, through KDS, sells genuine replacement parts, provides service mechanics to overhaul and repair engines, transmissions, reduction gears and related oilfield services equipment, rebuilds component parts or entire diesel engines, transmissions and reduction gears, and related equipment used in oilfield services, marine, power generation, on-highway and other industrial applications. The Company also rents equipment including generators, industrial compressors, high capacity lift trucks, and refrigeration trailers for use in a variety of industrial markets, and manufactures and remanufactures oilfield service equipment, including pressure pumping units, manufactures cementing and pumping equipment as well as coil tubing and well intervention equipment, electric power generation equipment, specialized electrical distribution and control equipment, and high capacity energy storage/battery systems for oilfield service and railroad customers. The Company sells and manufactures various products used in oil and gas and industrial applications, including those used in hydraulic fracturing and refrigeration systems that, as compared to conventional offerings, reduce emissions. These products made up approximately 24% of KDS’s revenues in 2023.

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During 2023, KDS generated 44% of the Company’s revenues, of which 78% was generated from service and parts and 22% from manufacturing. The results of KDS are largely influenced by cycles of the oilfield service industry and oil and gas operator and producer markets, marine, power generation, on-highway and other industrial markets.

Distribution and services revenues for 2023 increased 17% compared to 2022 and operating income increased 71% compared to 2022. In the commercial and industrial market, the increases in 2023 compared to 2022 were primarily attributable to strong economic activity across the U.S. which resulted in higher business levels in the marine and on-highway businesses. Increased product sales in Thermo King also contributed favorably to 2023 results. These results were partially offset by continuing supply chain constraints and delays. For 2023 and 2022, the commercial and industrial market contributed 59% and 56%, respectively, of the distribution and services revenues.

In the oil and gas market, revenues improved compared to 2022 due to higher oilfield activity which resulted in increased demand for new transmissions and parts in the distribution business. Although the manufacturing business was heavily impacted by supply chain delays, the business continues to experience increased orders and deliveries of new environmentally friendly pressure pumping equipment and power generation equipment for electric fracturing. For 2023 and 2022, the oil and gas market contributed 41% and 44%, respectively, of the distribution and services revenues.

The distribution and services operating margin for 2023 was 8.4% compared to 5.7% for 2022.

Outlook

Overall, the Company expects to deliver improved financial results in 2024. In KMT, barge utilization and customer demand remain strong, and rates continue to increase. In KDS, demand for products and services remains steady, and the Company continues to receive new orders in manufacturing. The Company remains mindful of the ever-changing economic landscape related to the impact of higher interest rates, and possible recessionary headwinds as it moves through 2024.

In the inland marine transportation market, the Company anticipates favorable market conditions driven by steady refinery and petrochemical plant utilization, minimal new barge construction across the industry, and a heavy year for industry maintenance. As a result, the Company expects further pricing improvements in the spot market, which currently represents 40% of inland revenues. Term contracts are also expected to continue to reset higher as a result of improved market conditions. In coastal marine, the Company expects steady customer demand and improved rates as the availability of equipment is reduced across the industry due to improved economic conditions.

KDS results are largely influenced by the cycles of the oil and gas, marine, power generation, on-highway and other related industrial markets. Despite the uncertainty from volatile commodity prices, the Company expects to yield incremental demand for OEM products, parts, and services in the segment. In commercial and industrial, strong demand for power generation and stable on-highway and marine repair markets is expected to help drive improved revenues. In oil and gas, the Company’s manufacturing backlog is expected to provide stable levels of activity through most of 2024 which will be offset by lower conventional oil and gas work. The Company anticipates extended lead times in the near-term to continue contributing to a volatile delivery schedule of new products in 2024.

Critical Accounting Policies and Estimates

The preparation of financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company evaluates its estimates and assumptions on an ongoing basis based on a combination of historical information and various other assumptions that are believed to be reasonable under the particular circumstances. Actual results may differ from these estimates based on different assumptions or conditions. The Company believes the critical accounting policies that most impact the consolidated financial statements are described below. It is also suggested that the Company’s significant accounting policies, as described in the Company’s financial statements in Note 1, Summary of Significant Accounting Policies, be read in conjunction with this Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Property, Maintenance and Repairs. Property is recorded at cost; improvements and betterments are capitalized as incurred. Depreciation is recorded using the straight-line method over the estimated useful lives of the individual assets. When property items are retired, sold, or otherwise disposed of, the related cost and accumulated depreciation are removed from the accounts with any gain or loss on the disposition included in the statement of earnings. Maintenance and repairs on vessels built for use on the inland waterways are charged to operating expense as incurred and includes the costs incurred in USCG inspections unless the shipyard extends the life, improves the operating capacity of the vessel, or replaces significant components of the vessel which results in the costs being capitalized. The Company’s ocean-going vessels are subject to regulatory drydocking requirements after certain periods of time to be inspected, have planned major maintenance performed and be recertified by the ABS. These recertifications generally occur twice in a five-year period. The Company defers the drydocking expenditures incurred on its ocean-going vessels due to regulatory marine

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inspections by the ABS and amortizes the costs of the shipyard over the period between drydockings, generally 30 or 60 months, depending on the type of major maintenance performed. Drydocking expenditures that extend the life, improve the operating capability of the vessel, or replace significant components of the vessel result in the costs being capitalized. Routine repairs and maintenance on ocean-going vessels are expensed as incurred. Interest is capitalized on the construction of new ocean-going vessels.

The Company performs an impairment assessment whenever events or changes in circumstances indicate that the carrying amount of long-lived assets may not be recoverable. If a triggering event is identified, the Company compares the carrying amount of the asset group to the estimated undiscounted future cash flows expected to result from the use of the asset group. If the carrying amount of the asset group exceeds the estimated undiscounted future cash flows, the Company measures the amount of the impairment by comparing the carrying amount of the asset group to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. There are many assumptions and estimates underlying the determination of an impairment event or loss, if any. The assumptions and estimates include, but are not limited to, estimated fair market value of the assets and estimated future cash flows expected to be generated by these assets, which are based on additional assumptions such as asset utilization, length of service the asset will be used, and estimated salvage values. Although the Company believes its assumptions and estimates are reasonable, deviations from the assumptions and estimates could produce a materially different result.

Goodwill. The excess of the purchase price over the fair value of identifiable net assets acquired in transactions accounted for as a purchase is included in goodwill. Management monitors the recoverability of goodwill on an annual basis, or whenever events or circumstances indicate that interim impairment testing is necessary. The amount of goodwill impairment, if any, is typically measured based on projected discounted future operating cash flows using an appropriate discount rate and valued based on the excess of a reporting unit’s carrying amount over its fair value, incorporating all tax impacts caused by the recognition of the impairment loss. The assessment of the recoverability of goodwill will be impacted if estimated future operating cash flows are not achieved. There are many assumptions and estimates underlying the determination of an impairment event or loss, if any. Although the Company believes its assumptions and estimates are reasonable, deviations from the assumptions and estimates could produce a materially different result.

Acquisitions

On July 14, 2023, the Company purchased 23 inland tank barges with a total capacity of 265,000 barrels from an undisclosed seller for $37 million in cash. The 23 tank barges transport petrochemicals and refined products on the Mississippi River System and the Gulf Intracoastal Waterway. The average age of the 23 barges was 14 years.

The Company purchased four inland tank barges from a leasing company for $0.5 million in cash during the 2023 third quarter. The Company had been leasing the barges prior to the purchase.

On March 31, 2022, the Company paid $3.9 million in cash to purchase assets of a gearbox repair company in KDS.

During 2021, the Company purchased four inland tank barges from a leasing company for $7.5 million in cash. The Company had been leasing the barges prior to the purchase.

On October 4, 2021, the Company paid $1.6 million in cash to purchase assets of an energy storage systems manufacturer based in Texas which have been key to the development of new power generation solutions for electric fracturing equipment.

Financing of these purchases and acquisitions was through borrowings under the Company’s Revolving Credit Facility and cash provided by operating activities.

Results of Operations

The following table sets forth the Company’s marine transportation and distribution and services revenues and the percentage of each to total revenues for the comparable periods (dollars in thousands):

	Year Ended December 31,
	2023		%			2022		%			2021		%
Marine transportation	$	1,721,937		56	%	$	1,616,967		58	%	$	1,322,918		59	%
Distribution and services		1,369,703		44			1,167,787		42			923,742		41
	$	3,091,640		100	%	$	2,784,754		100	%	$	2,246,660		100	%

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Marine Transportation

The following table sets forth a year over year comparison of KMT’s revenues, costs and expenses, operating income and operating margins (dollars in thousands):

	Year Ended December 31,
	2023			2022			% Change			2021			% Change
Marine transportation revenues	$	1,721,937		$	1,616,967			6	%	$	1,322,918			22	%
Costs and expenses:
Costs of sales and operating expenses		1,136,526			1,146,657			(1	)		924,380			24
Selling, general and administrative		134,641			128,340			5			119,017			8
Taxes, other than on income		27,602			28,235			(2	)		30,527			(8	)
Depreciation and amortization		184,225			177,551			4			185,979			(5	)
		1,482,994			1,480,783			—			1,259,903			18
Operating income	$	238,943		$	136,184			75	%	$	63,015			116	%
Operating margins		13.9	%		8.4	%					4.8	%

The following table shows the marine transportation markets serviced by the Company, the marine transportation revenue distribution, products moved and the drivers of the demand for the products the Company transports:

Markets Serviced	2023 Revenue Distribution	Products Moved	Drivers
Petrochemicals	51%	Benzene, Styrene, Methanol, Acrylonitrile, Xylene, Naphtha, Caustic Soda, Butadiene, Propylene	Consumer non-durables — 70% Consumer durables — 30%
Black Oil	26%	Residual Fuel Oil, Coker Feedstock, Vacuum Gas Oil, Asphalt, Carbon Black Feedstock, Crude Oil, Natural Gas Condensate, Ship Bunkers	Fuel for Power Plants and Ships, Feedstock for Refineries, Road Construction
Refined Petroleum Products	20%	Gasoline, No. 2 Oil, Jet Fuel, Heating Oil, Diesel Fuel, Ethanol	Vehicle Usage, Air Travel, Weather Conditions, Refinery Utilization
Agricultural Chemicals	3%	Anhydrous Ammonia, Nitrogen-Based Liquid Fertilizer, Industrial Ammonia	Corn, Cotton and Wheat Production, Chemical Feedstock Usage

2023 Compared to 2022

Marine Transportation Revenues

KMT’s revenues for 2023 increased 6% compared to 2022 and operating income increased 75%, compared to 2022. The increases for 2023 were primarily due to improved term and spot pricing and utilization in the inland market when compared to 2022. This was partially offset by various lock closures along the Gulf Intracoastal Waterway and Illinois River, resulting in higher delay days. In addition, several refinery outages also impacted utilization. Revenues and operating income in 2022 were impacted by record low water levels on the Mississippi River during the 2022 fourth quarter. Also, the 2022 first quarter was impacted by the COVID-19 Omicron variant as increased cases of the virus among the Company’s mariners led to crewing challenges, lost revenue and increased operating costs. For 2023 and 2022, the inland tank barge fleet contributed 82% and 79%, respectively, and the coastal fleet contributed 18% and 21%, respectively, of marine transportation revenues.

Overall inland tank barge utilization levels improved in 2023 as compared to 2022, ranging from the low to mid-90% range during the 2023 first quarter, the low 90% range during the 2023 second quarter, the high 80% range during the 2023 third quarter, and the low 90% range in the 2023 fourth quarter. During 2022, inland tank barge utilization levels ranged from the mid-80% range during the 2022 first quarter, the low 90% range during both the 2022 second and third quarters, and the low 90% range in the 2022 fourth quarter. Utilization in the 2023 fourth quarter improved from the 2023 third quarter, which was negatively impacted by Illinois River lock closures and several refinery outages.

Coastal tank barge utilization levels during 2023 averaged in the mid to high 90% range during both the 2023 first and second quarters, the mid-90% range during the 2023 third quarter, and the low to mid-90% range during the 2023 fourth quarter. For 2022, coastal tank barge utilization levels averaged in the low 90% range during both the 2022 first and second quarters and low to mid-90% range during both the 2022 third and fourth quarters.

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The petrochemical market, the Company’s largest market, contributed 51% of marine transportation revenues for 2023, reflecting increased rates, volumes and utilization from Gulf Coast petrochemical plants as a result of improved economic conditions and a reduced supply of barges across the industry due to a heavier than normal maintenance cycle as compared to 2022.

The black oil market, which contributed 26% of marine transportation revenues for 2023, reflecting improved demand as refinery utilization and production levels of refined petroleum products and fuel oils increased. During 2023, the Company transported crude oil and natural gas condensate produced from the Permian Basin and the Eagle Ford shale formation in Texas, both along the Gulf Intracoastal Waterway with inland vessels and in the Gulf of Mexico with coastal equipment. Additionally, the Company transported volumes of Utica natural gas condensate downriver from the Mid-Atlantic to the Gulf Coast and Canadian and Bakken crude downriver from the Midwest to the Gulf Coast.

The refined petroleum products market, which contributed 20% of marine transportation revenues for 2023, saw increased volumes in the inland market with improved refinery utilization and product levels.

The agricultural chemical market, which contributed 3% of marine transportation revenues for 2023, also experienced improved demand for transportation of both domestically produced and imported products.

Inland operations incurred 10,863 delay days in 2023, 6% more than the 10,244 delay days that occurred during 2022. Delay days measure the lost time incurred by a tow (towboat and one or more tank barges) during transit when the tow is stopped due to weather, lock conditions, or other navigational factors. Delay days for 2023 and 2022 were impacted by hurricanes and tropical storms, poor operating conditions due to heavy wind and fog along the Gulf Coast, low and high water conditions on the Mississippi River System, and various lock closures along the Gulf Intracoastal Waterway, due in part to lock maintenance projects. The 2023 third quarter was also impacted by lock closures on the Illinois River.

Approximately 60% of the inland marine transportation revenues were under term contracts and 40% were under spot contracts in 2023 and 2022. Term contracts provide the operations with a reasonably predictable revenue stream. Inland time charters, which insulate the Company from revenue fluctuations caused by weather and navigational delays and temporary market declines, represented 63% of the inland revenues under term contracts during 2023 and 58% during 2022. During 2023 and 2022, approximately 85% and 75%, respectively, of coastal revenues were under term contracts and 15% and 25%, respectively, were under spot contracts. Coastal time charters represented approximately 90% of coastal revenues under term contracts during both 2023 and 2022. Term contracts have contract terms of 12 months or longer, while spot contracts have contract terms of less than 12 months.

The following table summarizes the average range of pricing changes in term and spot contracts renewed during 2023 compared to contracts renewed during the corresponding quarter of 2022:

	Three Months Ended
	March 31, 2023	June 30, 2023	September 30, 2023	December 31, 2023
Inland market:
Term increase	10% – 12%	10% – 12%	7% – 9%	7% – 9%
Spot increase	23% – 26%	26% – 29%	14% – 16%	15% – 18%
Coastal market (a):
Term increase	10% – 12%	16% – 18%	10% – 12%	20% – 22%
Spot increase	20% – 23%	25% – 28%	31% – 33%	34% – 36%

(a)Spot and term contract pricing in the coastal market are contingent on various factors including geographic location, vessel capacity, vessel type, and product serviced.

Effective January 1, 2023, annual escalators for labor and the producer price index on a number of inland multi-year contracts resulted in rate increases on those contracts of approximately 9%, excluding fuel.

Marine Transportation Costs and Expenses

Total costs and expenses for 2023 were flat compared to 2022. Costs of sales and operating expenses for 2023 decreased 1% compared to 2022 primarily reflecting lower fuel costs which was partially offset by higher business activity levels and inflationary cost pressures.

The inland marine transportation fleet operated an average of 280 towboats during 2023, of which an average of 64 were chartered, compared to 271 during 2022, of which an average of 59 were chartered. The increase was primarily due to higher business activity levels. Generally, variability in demand or anticipated demand, as tank barges are added to or removed from the fleet, as chartered towboat availability changes, or as weather or water conditions dictate, the Company charters in or releases chartered towboats in an

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effort to balance horsepower needs with current requirements. The Company has historically used chartered towboats for approximately one-fourth of its horsepower requirements.

Inland operations consumed 48.1 million gallons of diesel fuel in 2023 compared to 48.4 million gallons consumed during 2022. The average price per gallon of diesel fuel consumed during 2023 was $3.08 per gallon compared to $3.70 per gallon for 2022. Fuel escalation and de-escalation clauses are typically included in term contracts and are designed to rebate fuel costs when prices decline and recover additional fuel costs when fuel prices rise; however, there is generally a 30 to 120 day delay before contracts are adjusted. Spot contracts do not have escalators for fuel.

Selling, general and administrative expenses for 2023 increased 5% compared to 2022 due to higher business activity levels and inflationary cost pressures. The increase is primarily due to higher salary and wage increases effective July 1, 2023 and increased incentive compensation, partially offset by lower legal costs. Selling, general and administrative expenses for 2022 were negatively impacted by severance expense in the 2022 second and fourth quarters.

Depreciation and amortization for 2023 increased slightly compared to 2022. The increase was primarily due to capital additions during 2023 and 2022.

Marine Transportation Operating Income and Operating Margins

KMT operating income for 2023 increased 75% compared to 2022. The operating margin was 13.9% for 2023 compared to 8.4% for 2022. The increase in operating income and operating margin were primarily due to increased barge utilization and higher term and spot contract pricing in the inland and coastal markets. The 2022 results were impacted by increased fuel prices as well as the impact of the COVID-19 Omicron variant during the 2022 first quarter.

Distribution and Services

The following table sets forth a year over year comparison of KDS’s revenues, costs and expenses, operating income and operating margins (dollars in thousands):

	Year Ended December 31,
	2023			2022			% Change			2021			% Change
Distribution and services revenues	$	1,369,703		$	1,167,787			17	%	$	923,742			26	%
Costs and expenses:
Costs of sales and operating expenses		1,040,905			913,624			14			728,855			25
Selling, general and administrative		187,424			163,642			15			141,100			16
Taxes, other than on income		7,051			6,708			5			5,607			20
Depreciation and amortization		19,842			16,776			18			20,573			(18	)
		1,255,222			1,100,750			14			896,135			23
Operating income	$	114,481		$	67,037			71	%	$	27,607			143	%
Operating margins		8.4	%		5.7	%					3.0	%

The following table shows the markets serviced by the Company, the revenue distribution, and the customers for each market:

Markets Serviced	2023 Revenue Distribution	Customers
Commercial and Industrial	59%	Inland River Carriers — Dry and Liquid, Offshore Towing — Dry and Liquid, Offshore Oilfield Services — Drilling Rigs & Supply Boats, Harbor Towing, Dredging, Great Lakes Ore Carriers, Pleasure Crafts, On and Off-Highway Transportation, Power Generation, Standby Power Generation, Pumping Stations, Mining
Oil and Gas	41%	Oilfield Services, Oil and Gas Operators and Producers

40

2023 Compared to 2022

Distribution and Services Revenues

KDS revenues for 2023 increased 17% compared to 2022. In the commercial and industrial market, the increase was primarily attributable to strong economic activity across the U.S. which resulted in higher business levels in the marine and on-highway businesses. For 2023 and 2022, the commercial and industrial market contributed 59% and 56%, respectively, of KDS revenues.

The oil and gas market revenues increase compared to 2022 primarily due to higher oilfield activity which resulted in increased demand for new transmissions and parts in the distribution business. Although the manufacturing business was heavily impacted by supply chain delays, the business continued to experience increased orders and deliveries of new environmentally friendly pressure pumping equipment and power generation equipment for electric fracturing. For 2023 and 2022, the oil and gas market contributed 41% and 44%, respectively, of KDS revenues.

Distribution and Services Costs and Expenses

Total costs and expenses for 2023 increased 14% compared to 2022 reflecting higher costs of sales and operating expenses as a result of inflationary cost pressures and higher demand in the marine and on-highway businesses in commercial and industrial markets, as well as increased demand in the oil and gas market due to higher oilfield activity levels.

Selling, general and administrative expenses for 2023 increased 15% compared to 2022. The increase was primarily due to continued inflationary cost pressures, higher business activity and annual compensation increases.

Depreciation and amortization for 2023 increased 18% compared to 2022. The increase was primarily due to increased capital spending during 2022 and 2023.

Distribution and Services Operating Income and Operating Margins

Operating income for KDS for 2023 increased 71% compared to 2022. The operating margin was 8.4% for 2023 compared to 5.7% for 2022. The results reflect increased business levels in both the commercial and industrial and oil and gas markets and ongoing cost management initiatives, which were partially offset by higher costs and expenses due to higher business activity.

General Corporate Expenses

General corporate expenses for 2023, 2022, and 2021 were $23.3 million, $18.6 million and $13.8 million, respectively. General corporate expenses were higher in 2023 compared to 2022 primarily due to higher legal and insurance costs. The 2023 first quarter also included costs related to the strategic review and shareholder engagement.

Gain on Disposition of Assets

The Company reported net gains on disposition of assets of $5.0 million, $8.3 million, and $5.8 million in 2023, 2022, and 2021, respectively. The net gains were predominantly from the sales or retirements of marine equipment.

Other Income and Expenses

The following table sets forth a year over year comparison of impairments and other charges, other income, noncontrolling interests, and interest expense (dollars in thousands):

	Year Ended December 31,
	2023			2022			% Change			2021			% Change
Impairments and other charges	$	—		$	—			0	%	$	(340,713	)		(100	)%
Other income	$	11,041		$	16,677			(34	)%	$	10,001			67	%
Noncontrolling interests	$	30		$	(470	)		(106	)%	$	(183	)		157	%
Interest expense	$	(52,008	)	$	(44,588	)		17	%	$	(42,469	)		5	%

Other Income

Other income for 2023, 2022, and 2021 includes income of $4.8 million, $13.9 million and $8.2 million, respectively, for all components of net benefit costs except the service cost component related to the Company’s defined benefit plans.

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Interest Expense

The following table sets forth average debt and average interest rate (dollars in thousands):

	Year Ended December 31,
	2023			2022			2021
Average debt	$	1,088,851		$	1,171,317		$	1,293,446
Average interest rate		4.7	%		3.8	%		3.2	%

Interest expense for 2023 increased 17% compared to 2022, primarily due to a higher average interest rate, partially offset by a lower average debt outstanding as a result of debt repayments.

(Provision) Benefit for Taxes on Income

Provision for taxes on income for 2023 increased 69% compared to 2022, primarily due to improved earnings before taxes on income as a result of increased business activity levels.

Financial Condition, Capital Resources and Liquidity

Balance Sheet

The following table sets forth a year over year comparison of the significant components of the balance sheets (dollars in thousands):

	December 31,
	2023		2022		% Change			2021		% Change
Assets:
Current assets	$	1,135,161	$	1,211,759		(6	)%	$	1,003,865		21	%
Property and equipment, net		3,861,105		3,633,462		6			3,678,515		(1	)
Operating lease right-of-use assets		152,216		154,507		(1	)		167,730		(8	)
Investment in affiliates		2,576		2,171		19			2,134		2
Goodwill		438,748		438,748		—			438,748		—
Other intangibles, net		42,927		51,463		(17	)		60,070		(14	)
Other assets		89,464		62,814		42			48,001		31
	$	5,722,197	$	5,554,924		3	%	$	5,399,063		3	%
Liabilities and stockholders’ equity:
Current liabilities	$	675,795	$	642,197		5	%	$	543,772		18	%
Long-term debt, net — less current portion		1,008,527		1,076,326		(6	)		1,161,433		(7	)
Deferred income taxes		696,557		625,884		11			574,152		9
Operating lease liabilities — less current portion		138,811		142,140		(2	)		159,672		(11	)
Other long-term liabilities		15,830		23,209		(32	)		71,252		(67	)
Total equity		3,186,677		3,045,168		5			2,888,782		5
	$	5,722,197	$	5,554,924		3	%	$	5,399,063		3	%

2023 Compared to 2022

Current assets as of December 31, 2023 decreased 6% compared to December 31, 2022. Trade accounts receivable increased 9% primarily due to increased business activity in both KMT and KDS. Other accounts receivable decreased 55% as the Company received its tax refund of $70.4 million plus accrued interest in April 2023.

Property and equipment, net of accumulated depreciation, at December 31, 2023 increased 6% compared to December 31, 2022. The increase reflected $411.3 million of capital additions (including accrued capital expenditures) and $37.5 million of acquisitions of barge equipment, partially offset by $203.1 million of depreciation expense and $18.1 million of property disposals, more fully described under Cash Flows and Capital Expenditures below.

Operating lease right-of-use assets as of December 31, 2023 decreased 1% compared to December 31, 2022, primarily due to lease amortization expense, partially offset by new leases acquired.

Other intangibles, net, as of December 31, 2023 decreased 17% compared to December 31, 2022, primarily due to amortization.

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Other assets as of December 31, 2023 increased 42% compared to December 31, 2022, primarily due to an increase in pension assets as a result of an improved funded status.

Current liabilities as of December 31, 2023 increased 5% compared to December 31, 2022. Accounts payable decreased 3%, primarily due to timing of payments. Accrued liabilities increased 12%, primarily due to increased insurance claims and higher employee incentive compensation accruals. Deferred revenues increased 13%, primarily due to deposits on equipment expected to be shipped in 2024 in KDS.

Long-term debt, net – less current portion, as of December 31, 2023, decreased 6% compared to December 31, 2022, primarily reflecting the maturity of the 3.29% senior notes due February 27, 2023, partially offset by borrowings under the 3.46% and 3.51% senior notes due January 19, 2033 and the 2027 Revolving Credit Facility.

Deferred income taxes as of December 31, 2023 increased 11% compared to December 31, 2022, primarily reflecting the 2023 deferred tax provision of $65.3 million.

Operating lease liabilities – less current portion, as of December 31, 2023 decreased 2% compared to December 31, 2022, primarily due to lease payments made, partially offset by new leases acquired and liability accretion.

Other long-term liabilities as of December 31, 2023 decreased 32% compared to December 31, 2022, primarily due to a decrease in pension liabilities due to pension contributions and amortization of intangible liabilities.

Total equity as of December 31, 2023 increased 5% compared to December 31, 2022, primarily due to net earnings attributable to Kirby of $222.9 million and other comprehensive income of $18.2 million for 2023, partially offset by treasury stock purchases of $112.8 million.

Retirement Plans

The Company sponsors a defined benefit plan for its inland vessel personnel and shore based tankermen. The plan benefits are based on an employee’s years of service and compensation. The plan assets consist primarily of equity and fixed income securities. The Company’s pension plan funding strategy is to make annual contributions in amounts equal to or greater than amounts necessary to meet minimum government funding requirements. No pension contributions to that plan were made in 2023, 2022 or 2021.

On April 12, 2017, the Company amended its pension plan to cease all benefit accruals for periods after May 31, 2017 for certain participants. Participants grandfathered and not impacted were those, as of the close of business on May 31, 2017, who either (a) had completed 15 years of pension service or (b) had attained age 50 and completed 10 years of pension service. Participants non-grandfathered are eligible to receive discretionary 401(k) plan contributions.

On February 14, 2018, with the acquisition of Higman Marine, Inc. (“Higman”), the Company assumed Higman’s pension plan (the “Higman Pension Plan”) for its inland vessel personnel and office staff. On March 27, 2018, the Company amended the Higman Pension Plan to close it to all new entrants and cease all benefit accruals for periods after May 15, 2018 for all participants. The Company made contributions to the Higman Pension Plan of $8.2 million, $0.9 million and $0.5 million for the years ended December 31, 2023, 2022 and 2021, respectively.

The aggregate fair value of plan assets of the Company’s pension plans was $375.9 million and $341.1 million at December 31, 2023, and 2022, respectively.

The Company’s investment strategy focuses on total return on invested assets (capital appreciation plus dividend and interest income). The primary objective in the investment management of assets is to achieve long-term growth of principal while avoiding excessive risk. Risk is managed through diversification of investments within and among asset classes, as well as by investing in asset classes offering sufficient liquidity and trading history.

The Company makes various assumptions when determining defined benefit plan costs including, but not limited to, the current discount rate and the expected long-term return on plan assets. Discount rates are determined annually and are based on a yield curve that consists of a hypothetical portfolio of high quality corporate bonds with maturities matching the projected benefit cash flows. The Company used discount rates of 5.1% for the Kirby pension plan and 5.2% for the Higman pension plan in 2023 and 5.5% for both the Kirby pension plan and the Higman pension plan in 2022. The Company estimates that every 0.1% decrease in the discount rate results in an increase in the accumulated benefit obligation (“ABO”) of approximately $4.3 million. The Company assumed that plan assets would generate a long-term rate of return of 6.75% in both 2023 and 2022. The Company developed its expected long-term rate of return assumption by evaluating input from investment consultants and comparing historical returns for various asset classes with its actual and targeted plan investments. The Company believes that long-term asset allocation, on average, will approximate the targeted allocation.

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Long-Term Financing

The following table summarizes the Company’s outstanding debt (in thousands):

	December 31,
	2023			2022
Long-term debt, including current portion:
Revolving Credit Facility due July 29, 2027 (a)	$	44,000		$	—
Term Loan due July 29, 2027 (a)		170,000			170,000
3.29% senior notes due February 27, 2023		—			350,000
4.2% senior notes due March 1, 2028		500,000			500,000
3.46% senior notes due January 19, 2033		60,000			60,000
3.51% senior notes due January 19, 2033		240,000			—
Credit line due June 30, 2024		—			—
Bank notes payable		8,068			3,292
		1,022,068			1,083,292
Unamortized debt discount and issuance costs (b)		(5,473	)		(3,674	)
	$	1,016,595		$	1,079,618

(a)Variable interest rate of 6.8% and 5.8% at December 31, 2023 and 2022, respectively.

(b)Excludes $1.8 million attributable to the 2027 Revolving Credit Facility included in other assets at December 31, 2022.

At the beginning of 2022, the Company had an amended and restated credit agreement (the “2024 Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank, that allowed for an $850 million unsecured revolving credit facility (the “2024 Revolving Credit Facility”) and an unsecured term loan (the “2024 Term Loan”) with a maturity date of March 27, 2024. The 2024 Term Loan was prepayable, in whole or in part, without penalty.

On July 29, 2022, the Company entered into a new credit agreement (the “2027 Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank that allows for a $500 million unsecured revolving credit facility (the “2027 Revolving Credit Facility”) and a $250 million unsecured term loan (the “2027 Term Loan”) with a maturity date of July 29, 2027. The 2027 Credit Agreement replaced the 2024 Credit Agreement. In conjunction with entering into the 2027 Credit Agreement, on July 29, 2022, the Company borrowed $35 million under the 2027 Revolving Credit Facility and $250 million under the 2027 Term Loan to repay borrowings under the 2024 Term Loan. In the fourth quarter of 2022, the Company repaid $80.0 million under the 2027 Term Loan prior to scheduled maturities. As a result, no repayments are required until June 30, 2025. Outstanding letters of credit under the 2027 Revolving Credit Facility were $6,000 and available borrowing capacity was $456.0 million as of December 31, 2023.

The 2027 Term Loan is repayable in quarterly installments, with no repayments until June 30, 2025, in increasing percentages of the original principal amount of the loan, with the remaining unpaid balance of approximately $43.8 million payable upon maturity, assuming no prepayment. The 2027 Term Loan is prepayable, in whole or in part, without penalty. The 2027 Credit Agreement provides for a variable interest rate based on the Secured Overnight Financing Rate (“SOFR”) or a base rate calculated with reference to the prime rate quoted by The Wall Street Journal, the Federal Reserve Bank of New York Rate plus 0.5%, or the adjusted SOFR rate for a one month interest period plus 1.0%, among other factors (the “Alternate Base Rate”). The interest rate varies with the Company’s credit rating and is currently 137.5 basis points over SOFR or 37.5 basis points over the Alternate Base Rate. The 2027 Credit Agreement contains certain financial covenants including an interest coverage ratio and debt-to-capitalization ratio. In addition to financial covenants, the 2027 Credit Agreement contains covenants that, subject to exceptions, restrict debt incurrence, mergers and acquisitions, sales of assets, dividends and investments, liquidations and dissolutions, capital leases, transactions with affiliates, and changes in lines of business. The 2027 Credit Agreement specifies certain events of default, upon the occurrence of which the maturity of the outstanding loans may be accelerated, including the failure to pay principal or interest, violation of covenants and default on other indebtedness, among other events. Borrowings under the 2027 Credit Agreement may be used for general corporate purposes including acquisitions. The 2027 Revolving Credit Facility includes a $25 million commitment which may be used for standby letters of credit.

The Company has $500 million of 4.2% senior unsecured notes due March 1, 2028 (the “2028 Notes”) with U.S. Bank National Association, as trustee. No principal payments are required until maturity. Interest payments of $10.5 million are due semi-annually on March 1 and September 1 of each year. The 2028 Notes are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. The 2028 Notes contain certain covenants on the part of the Company, including covenants relating to liens, sale-leasebacks, asset sales and mergers, among others. The 2028 Notes also specify certain events of default, upon the occurrence of which the maturity of the notes may be accelerated, including failure to pay principal and interest, violation of covenants or default on other indebtedness, among others.

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On February 3, 2022, the Company entered into a note purchase agreement for the issuance of $300 million of unsecured senior notes with a group of institutional investors, consisting of $60 million of 3.46% series A notes (“Series A Notes”) and $240 million of 3.51% series B notes (“Series B Notes”), each due January 19, 2033 (collectively, the “2033 Notes”). The Series A Notes were issued on October 20, 2022, and the Series B Notes were issued on January 19, 2023. No principal payments will be required until maturity. Beginning in 2023, interest payments of $5.3 million will be due semi-annually on January 19 and July 19 of each year, with the exception of the first payment on January 19, 2023, which was $0.5 million. The 2033 Notes are unsecured and rank equally in right of payment with the Company's other unsecured senior indebtedness. The 2033 Notes contain certain covenants on the part of the Company, including an interest coverage covenant, a debt-to-capitalization covenant, and covenants relating to liens, asset sales and mergers, among others. The 2033 Notes also specify certain events of default, upon the occurrence of which the maturity of the notes may be accelerated, including failure to pay principal and interest, violation of covenants or default on other indebtedness, among others. The 3.29% unsecured senior notes due February 27, 2023 (the “2023 Notes”) were repaid using a combination of the proceeds from the issuance of the 2033 Notes and availability under the 2027 Revolving Credit Facility.

The Company has a $10.0 million line of credit (“Credit Line”) with Bank of America, N.A. (“Bank of America”) for short-term liquidity needs and letters of credit, with a maturity date of June 30, 2024. Outstanding letters of credit under the $10.0 million credit line were $7.3 million and available borrowing capacity was $2.7 million as of December 31, 2023.

The Company also had $8.1 million and $3.3 million of short-term unsecured loans outstanding, as of December 31, 2023 and 2022, respectively, related to its Colombia operations.

As of December 31, 2023, the Company was in compliance with all covenants under its debt instruments. For additional information about the Company’s debt instruments, see Note 5, Long-Term Debt.

Cash Flow and Capital Expenditures

The Company generated net cash provided by operating activities of $540.2 million, $294.1 million, and $321.6 million for the years ended December 31, 2023, 2022, and 2021, respectively. The 84% increase in 2023 as compared to 2022 was primarily due to higher revenues and operating income in KMT and KDS and the receipt of the IRS refund of $70.4 million plus accrued interest in April 2023, which more than offset an increase in trade accounts receivable, primarily due to higher revenues and timing of collections. Increases in KMT revenues and operating income were driven by increased barge utilization and higher term and spot contract pricing in the inland and coastal markets during 2023.

During 2023, 2022, and 2021, the Company generated cash of $26.1 million, $36.9 million, and $51.3 million, respectively, from proceeds from the disposition of assets, and $4.2 million, $3.9 million, and $0.6 million, respectively, from proceeds from the exercise of stock options.

For 2023, cash generated was used for capital expenditures of $401.7 million (net of an increase in accrued capital expenditures of $9.6 million), including $46.7 million for specialized inland equipment construction and $355.0 million primarily for upgrading existing marine equipment, new electric fracturing equipment, and KMT and KDS facilities. The Company also used $37.5 million for acquisitions of businesses and marine equipment, more fully described under Acquisitions above.

For 2022, cash generated was used for capital expenditures of $172.6 million (net of an increase in accrued capital expenditures of $3.0 million), including $8.3 million for inland towboat construction and $164.3 million primarily for upgrading existing marine equipment and marine transportation and distribution and services facilities. The Company also used $3.9 million for acquisitions of businesses and marine equipment, more fully described under Acquisitions above.

Treasury Stock Purchases

During 2023, the Company purchased 1.5 million shares of its common stock for $112.8 million, at an average price of $75.95 per share. Subsequent to December 31, 2023 and through February 16, 2024, the Company purchased an additional 235,247 shares of its common stock for $18.7 million, at an average price of $79.34 per share. During 2022, the Company purchased 0.4 million shares of its common stock for $22.9 million, at an average price of $59.32 per share. The Company did not purchase any treasury stock during 2021. On January 30, 2023, the Board approved a five million share increase in the Company’s purchase authorization. As of February 16, 2024, the Company had approximately 4.3 million shares available under its existing purchase authorizations. Historically, treasury stock purchases have been financed through operating cash flows and borrowings under the Company’s Revolving Credit Facility. The Company is authorized to purchase its common stock on the New York Stock Exchange and in privately negotiated transactions. When purchasing its common stock, the Company is subject to price, trading volume and other market considerations. Shares purchased may be used for reissuance upon the exercise of stock options or the granting of other forms of incentive compensation, in future acquisitions for stock or for other appropriate corporate purposes. For more information about stock purchases in the 2023 fourth quarter, see Item 5 Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

45

Liquidity and Capital Resources

Funds generated from operations are available for acquisitions, capital expenditure projects, common stock purchases, repayments of borrowings and for other corporate and operating requirements. In addition to net cash flow provided by operating activities, as of February 16, 2024, the Company had cash equivalents of $53.4 million, availability of $381.0 million under its Revolving Credit Facility and $2.7 million available under its Credit Line.

Neither the Company, nor any of its subsidiaries, is obligated on any debt instrument, swap agreement, or any other financial instrument or commercial contract which has a rating trigger, except for pricing grids on its 2027 Credit Agreement.

The Company expects to continue to be able to fund expenditures for acquisitions, capital construction projects, common stock purchases, repayment of borrowings, and for other operating requirements both in the short term and in the long term from a combination of available cash and cash equivalents, funds generated from operating activities, and available financing arrangements.

The 2027 Revolving Credit Facility’s commitment is in the amount of $500 million and expires July 29, 2027. The 4.2% senior unsecured notes do not mature until March 1, 2028 and require no prepayments. The 2027 Term Loan in the amount of $250 million is subject to quarterly installments, beginning June 30, 2025, in increasing percentages of the original principal amount of the loan, with the remaining unpaid balance of approximately $43.8 million payable on July 29, 2027, assuming no prepayments. The 2027 Term Loan is prepayable, in whole or in part, without penalty. The 2033 Notes do not mature until January 19, 2033 and require no prepayment.

There are numerous factors that may negatively impact the Company’s cash flow in 2024. For a list of significant risks and uncertainties that could impact cash flows, see Note 14, Contingencies and Commitments in the financial statements, and Item 1A — Risk Factors. Amounts available under the Company’s existing financing arrangements are subject to the Company continuing to meet the covenants of the credit facilities as described in Note 5, Long-Term Debt in the financial statements.

The Company has issued guaranties or obtained standby letters of credit and performance bonds supporting performance by the Company and its subsidiaries of contractual or contingent legal obligations of the Company and its subsidiaries incurred in the ordinary course of business. The aggregate notional value of these instruments is $26.7 million at December 31, 2023, including $12.1 million in letters of credit and $14.6 million in performance bonds. All of these instruments have an expiration date within two years. The Company does not believe demand for payment under these instruments is likely and expects no material cash outlays to occur in connection with these instruments.

The Company’s marine transportation term contracts typically contain fuel escalation clauses, or the customer pays for the fuel. However, there is generally a 30 to 120 day delay before contracts are adjusted depending on the specific contract. In general, the fuel escalation clauses are effective over the long-term in allowing the Company to recover changes in fuel costs due to fuel price changes. However, the short-term effectiveness of the fuel escalation clauses can be affected by a number of factors including, but not limited to, specific terms of the fuel escalation formulas, fuel price volatility, navigating conditions, tow sizes, trip routing, and the location of loading and discharge ports that may result in the Company over or under recovering its fuel costs. The Company’s spot contract rates generally reflect current fuel prices at the time the contract is signed but do not have escalators for fuel.

The Company currently leases various facilities and equipment under cancelable and noncancelable operating leases. Future minimum lease payments under operating leases that have initial noncancelable lease terms in excess of one year are detailed in Note 6, Leases. Lease payments for towing vessels exclude non-lease components. The Company estimates that non-lease components comprise approximately 70% of charter rental costs, related to towboat crew costs, maintenance and insurance.

The Company’s pension plan funding strategy is to make annual contributions in amounts equal to or greater than amounts necessary to meet minimum government funding requirements. The ABO is based on a variety of demographic and economic assumptions, and the pension plan assets’ returns are subject to various risks, including market and interest rate risk, making an accurate prediction of the pension plan contribution difficult resulting in the Company electing to only make an expected pension contribution forecast of one year. As of December 31, 2023, the Company’s pension plan funding was 115% of the pension plans’ ABO, including the Higman pension plan. The Company expects to make additional pension contributions of $1.8 million in 2024.

The Company has certain mechanisms designed to help mitigate the impacts of rising costs. For example, KMT has long-term contracts which generally contain cost escalation clauses whereby certain costs, including fuel as noted above, can be largely passed through to its customers. Spot contract rates include the cost of fuel and are subject to market volatility. In KDS, the cost of major components for large manufacturing orders is secured with suppliers at the time a customer order is finalized, which somewhat limits exposure to inflation. The repair portion of KDS is based on prevailing current market rates.

Accounting Standards

For a discussion of recently issued accounting standards, see Note 1, Summary of Significant Accounting Policies.

46

Item 7A. Quantitative and Qualitative Disclosures about Market Risk

The Company is exposed to risk from changes in interest rates on certain of its outstanding debt. The outstanding loan balances under the Company’s bank credit facilities bear interest at variable rates based on prevailing short-term interest rates in the United States and Europe. A 1% increase in variable interest rates would impact the 2023 interest expense by $2.1 million based on balances outstanding at December 31, 2023, and would change the fair value of the Company’s debt by approximately 4.0%.

Item 8. Financial Statements and Supplementary Data

The response to this item is submitted as a separate section of this report (see Item 15, page 78 and pages 49 to 77 of this report).

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Not applicable.

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Item 9A. Controls and Procedures

Disclosure Controls and Procedures. The Company’s management, with the participation of the Chief Executive Officer and the Chief Financial Officer, has evaluated the Company’s disclosure controls and procedures (as defined in Rule 13a-15(e) under the Securities Exchange Act of 1934 (“Exchange Act”)), as of December 31, 2023, as required by Rule 13a-15(b) under the Exchange Act. Based on that evaluation, the Chief Executive Officer and the Chief Financial Officer concluded that, as of December 31, 2023, the disclosure controls and procedures were effective to ensure that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act (i) is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms and (ii) is accumulated and communicated to the Company’s management, including the Chief Executive Officer and the Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

Management’s Annual Report on Internal Control Over Financial Reporting. Management of the Company is responsible for establishing and maintaining adequate internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act). The Company’s management, with the participation of the Chief Executive Officer and the Chief Financial Officer, evaluated the effectiveness of the Company’s internal control over financial reporting as of December 31, 2023 using the framework in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on that evaluation, management concluded that the Company’s internal control over financial reporting was effective as of December 31, 2023. KPMG LLP, the Company’s independent registered public accounting firm, has audited the Company’s internal control over financial reporting, as stated in their report which is included herein.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Changes in Internal Control Over Financial Reporting. There were no changes in the Company’s internal control over financial reporting during the quarter ended December 31, 2023 that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.

Item 9B. Other Information

During the three months ended December 31, 2023, no director or officer of the Company adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Not applicable

PART III

Items 10 Through 14.

The information for these items is incorporated by reference to the definitive proxy statement to be filed by the Company with the Commission pursuant to Regulation 14A within 120 days of the close of the fiscal year ended December 31, 2023, except for the information regarding executive officers which is provided under Item 1.

48

Report of Independent Registered Public Accounting Firm

To the Stockholders and Board of Directors

Kirby Corporation:

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of Kirby Corporation and subsidiaries (the Company) as of December 31, 2023 and 2022, the related consolidated statements of earnings, comprehensive income, stockholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2023, and the related notes (collectively, the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2023, in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission, and our report dated February 20, 2024 expressed an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these consolidated financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of a critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Evaluation of potential impairment indicators for coastal marine transportation equipment

As discussed in Note 1 to the consolidated financial statements, the Company performs an impairment assessment when circumstances indicate that the carrying amount of its long-lived assets may not be recoverable. If a triggering event is identified, the Company compares the carrying amount of the asset group to the estimated undiscounted future cash flows expected to result from the use of the asset group. If the carrying amount of the asset group exceeds the estimated undiscounted future cash flows, the Company measures the amount of the impairment by comparing the carrying amount of the asset group to its estimated fair value. Recoverability of marine transportation equipment is assessed based on vessel classes. Marine Transportation equipment as of December 31, 2023, was $5,029,653,000, a portion of which related to coastal marine transportation equipment.

We identified the evaluation of potential impairment indicators for coastal marine transportation equipment as a critical audit matter. Evaluating the Company’s judgments in determining whether there was a triggering event required a high degree of subjective auditor judgment.

The following are the primary procedures we performed to address this critical audit matter. We evaluated the design and tested the operating effectiveness of certain internal controls related to the Company’s process to identify and assess triggering events that indicate that the carrying amount of coastal marine transportation equipment may not be recoverable. This included controls related

49

to the consideration of contract pricing by vessel class and market conditions in the determination of a triggering event. We assessed the Company’s identification of triggering events, including consideration of executed contract pricing and break-even costs by vessel class in addition to other certain qualitative considerations. We compared certain data used by the Company to relevant executed contracts, historical results, and analyst and industry reports. We evaluated the Company’s responses related to the elements considered and whether the Company omitted any significant internal or external elements in its evaluation.

/s/ KPMG LLP

We have served as the Company’s auditor since 1992.

Houston, Texas

February 20, 2024

50

Report of Independent Registered Public Accounting Firm

To the Stockholders and Board of Directors

Kirby Corporation:

Opinion on Internal Control Over Financial Reporting

We have audited Kirby Corporation and subsidiaries' (the Company) internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated balance sheets of the Company as of December 31, 2023 and 2022, the related consolidated statements of earnings, comprehensive income, stockholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2023, and the related notes (collectively, the consolidated financial statements), and our report dated February 20, 2024 expressed an unqualified opinion on those consolidated financial statements.

Basis for Opinion

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management's Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audit also included performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

Definition and Limitations of Internal Control Over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ KPMG LLP

Houston, Texas

February 20, 2024

51

KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

	December 31,
	2023			2022
	($ in thousands)
ASSETS
Current assets:
Cash and cash equivalents	$	32,577		$	80,577
Accounts receivable:
Trade — less allowance for doubtful accounts of $7,636 ($7,684 in 2022)		526,691			483,406
Other		52,025			114,556
Inventories — net		454,389			461,848
Prepaid expenses and other current assets		69,479			71,372
Total current assets		1,135,161			1,211,759
Property and equipment — net		3,861,105			3,633,462
Operating lease right-of-use assets		152,216			154,507
Investment in affiliates		2,576			2,171
Goodwill		438,748			438,748
Other intangibles, net		42,927			51,463
Other assets		89,464			62,814
Total assets	$	5,722,197		$	5,554,924
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Bank notes payable	$	8,068		$	3,292
Income taxes payable		1,486			323
Accounts payable		269,378			278,081
Accrued liabilities:
Interest		13,114			11,630
Insurance premiums and claims		84,825			65,088
Employee compensation		69,075			55,851
Taxes — other than on income		31,555			30,169
Other		30,377			42,014
Current portion of operating lease liabilities		33,340			36,444
Deferred revenues		134,577			119,305
Total current liabilities		675,795			642,197
Long-term debt, net — less current portion		1,008,527			1,076,326
Deferred income taxes		696,557			625,884
Operating lease liabilities — less current portion		138,811			142,140
Other long-term liabilities		15,830			23,209
Total long-term liabilities		1,859,725			1,867,559
Contingencies and commitments		—			—
Equity:
Kirby stockholders’ equity:
Common stock, $0.10 par value per share. Authorized 120,000,000 shares, issued 65,472,000		6,547			6,547
Additional paid-in capital		863,963			859,345
Accumulated other comprehensive income — net		35,006			16,853
Retained earnings		2,691,665			2,468,730
Treasury stock — at cost, 6,843,000 shares in 2023 and 5,565,000 shares in 2022		(411,750	)		(308,598	)
Total Kirby stockholders’ equity		3,185,431			3,042,877
Noncontrolling interests		1,246			2,291
Total equity		3,186,677			3,045,168
Total liabilities and equity	$	5,722,197		$	5,554,924

See accompanying notes to consolidated financial statements.

52

KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES

CONSOLIDATED STATEMENTS OF EARNINGS

	Year Ended December 31,
	2023			2022			2021
	($ in thousands, except per share amounts)
Revenues:
Marine transportation	$	1,721,937		$	1,616,967		$	1,322,918
Distribution and services		1,369,703			1,167,787			923,742
Total revenues		3,091,640			2,784,754			2,246,660
Costs and expenses:
Costs of sales and operating expenses		2,180,422			2,060,941			1,652,961
Selling, general and administrative		335,213			302,692			266,911
Taxes, other than on income		34,766			35,071			36,251
Depreciation and amortization		211,156			201,443			213,718
Impairments and other charges		—			—			340,713
Gain on disposition of assets		(5,009	)		(8,279	)		(5,761	)
Total costs and expenses		2,756,548			2,591,868			2,504,793
Operating income (loss)		335,092			192,886			(258,133	)
Other income		11,041			16,677			10,001
Interest expense		(52,008	)		(44,588	)		(42,469	)
Earnings (loss) before taxes on income		294,125			164,975			(290,601	)
(Provision) benefit for taxes on income		(71,220	)		(42,214	)		43,830
Net earnings (loss)		222,905			122,761			(246,771	)
Less: Net (earnings) loss attributable to noncontrolling interests		30			(470	)		(183	)
Net earnings (loss) attributable to Kirby	$	222,935		$	122,291		$	(246,954	)
Net earnings (loss) per share attributable to Kirby common stockholders:
Basic	$	3.74		$	2.04		$	(4.11	)
Diluted	$	3.72		$	2.03		$	(4.11	)

See accompanying notes to consolidated financial statements.

53

KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

	Year Ended December 31,
	2023		2022			2021
	($ in thousands)
Net earnings (loss)	$	222,905	$	122,761		$	(246,771	)
Other comprehensive income, net of taxes:
Pension and postretirement benefits		16,728		43,868			36,547
Foreign currency translation adjustments		1,425		(1,049	)		(1,061	)
Total other comprehensive income, net of taxes		18,153		42,819			35,486
Total comprehensive income (loss), net of taxes		241,058		165,580			(211,285	)
Net (earnings) loss attributable to noncontrolling interests		30		(470	)		(183	)
Comprehensive income (loss) attributable to Kirby	$	241,088	$	165,110		$	(211,468	)

See accompanying notes to consolidated financial statements.

54

KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS

	Year Ended December 31,
	2023			2022			2021
	($ in thousands)
Cash flows from operating activities:
Net earnings (loss)	$	222,905		$	122,761		$	(246,771	)
Adjustments to reconcile net earnings (loss) to net cash provided by operations:
Depreciation and amortization		211,156			201,443			213,718
Provision (credit) for doubtful accounts		402			1,183			(138	)
Provision (benefit) for deferred income taxes		65,298			37,782			(44,419	)
Gain on disposition of assets		(5,009	)		(8,279	)		(5,761	)
Impairments and other charges		—			—			340,713
Amortization of share-based compensation		14,941			13,865			15,713
Amortization of major maintenance costs		28,966			29,031			33,213
Other		(3,338	)		(283	)		(640	)
Increase (decrease) in cash flows resulting from changes in:
Accounts receivable		(50,135	)		(31,550	)		29,126
Inventory		7,694			(127,095	)		(19,248	)
Other assets		(37,688	)		(27,801	)		(38,335	)
Income taxes payable		71,604			1,975			480
Accounts payable		(18,271	)		75,996			15,951
Accrued and other liabilities		31,703			5,100			27,974
Net cash provided by operating activities		540,228			294,128			321,576
Cash flows from investing activities:
Capital expenditures		(401,730	)		(172,606	)		(98,015	)
Acquisitions of businesses and marine equipment, net of cash acquired		(37,500	)		(3,900	)		(9,115	)
Proceeds from disposition of assets and other		26,081			36,905			51,342
Net cash used in investing activities		(413,149	)		(139,601	)		(55,788	)
Cash flows from financing activities:
Borrowings (payments) on bank credit facilities, net		48,776			1,358			(248,105	)
Borrowings on long-term debt		240,000			310,000			—
Payments on long-term debt		(350,000	)		(395,000	)		(60,000	)
Payment of debt issue costs		(1,254	)		(1,977	)		—
Proceeds from exercise of stock options		4,209			3,887			629
Payments related to tax withholding for share-based compensation		(3,908	)		(3,408	)		(2,856	)
Treasury stock purchases		(112,803	)		(22,901	)		—
Return of investment to noncontrolling interests and other		(99	)		(722	)		(981	)
Net cash used in financing activities		(175,079	)		(108,763	)		(311,313	)
Increase (decrease) in cash and cash equivalents		(48,000	)		45,764			(45,525	)
Cash and cash equivalents, beginning of year		80,577			34,813			80,338
Cash and cash equivalents, end of year	$	32,577		$	80,577		$	34,813
Supplemental disclosures of cash flow information:
Cash paid (received) during the period:
Interest paid	$	49,317		$	42,816		$	40,878
Income taxes paid (refunded), net	$	(65,787	)	$	2,553		$	(116,648	)
Operating cash outflow from operating leases	$	43,954		$	44,229		$	44,089
Non-cash investing activity:
Capital expenditures included in accounts payable	$	9,567		$	2,996		$	18,633
Right-of-use assets obtained in exchange for lease obligations	$	39,153		$	22,799		$	33,842

See accompanying notes to consolidated financial statements.

55

KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

	Common Stock				Additional Paid-in-			Accumulated Other Comprehensive			Retained			Treasury Stock						Noncontrolling
	Shares		Amount		Capital			Income			Earnings			Shares			Amount			Interests			Total
	(in thousands)
Balance at December 31, 2020		65,472	$	6,547	$	844,979		$	(61,452	)	$	2,593,393			(5,434	)	$	(299,161	)	$	3,247		$	3,087,553
Stock option exercises		—		—		21			—			—			12			608			—			629
Issuance of stock for equity awards, net of forfeitures		—		—		(6,201	)		—			—			113			6,201			—			—
Tax withholdings on equity award vesting		—		—		—			—			—			(52	)		(2,856	)		—			(2,856	)
Amortization of share-based compensation		—		—		15,713			—			—			—			—			—			15,713
Total comprehensive loss, net of taxes		—		—		—			35,486			(246,954	)		—			—			183			(211,285	)
Return of investment to noncontrolling interests		—		—		—			—			—			—			—			(972	)		(972	)
Balance at December 31, 2021		65,472	$	6,547	$	854,512		$	(25,966	)	$	2,346,439			(5,361	)	$	(295,208	)	$	2,458		$	2,888,782
Stock option exercises		—		—		757			—			—			58			3,130			—			3,887
Issuance of stock for equity awards, net of forfeitures		—		—		(9,789	)		—			—			178			9,789			—			—
Tax withholdings on equity award vesting		—		—		—			—			—			(54	)		(3,408	)		—			(3,408	)
Amortization of share-based compensation		—		—		13,865			—			—			—			—			—			13,865
Treasury stock purchases		—		—		—			—			—			(386	)		(22,901	)		—			(22,901	)
Total comprehensive income, net of taxes		—		—		—			42,819			122,291			—			—			470			165,580
Return of investment to noncontrolling interests		—		—		—			—			—			—			—			(637	)		(637	)
Balance at December 31, 2022		65,472	$	6,547	$	859,345		$	16,853		$	2,468,730			(5,565	)	$	(308,598	)	$	2,291		$	3,045,168
Stock option exercises		—		—		453			—			—			71			3,755			—			4,208
Issuance of stock for equity awards, net of forfeitures		—		—		(10,776	)		—			—			194			10,776			—			—
Tax withholdings on equity award vesting		—		—		—			—			—			(58	)		(3,908	)		—			(3,908	)
Amortization of share-based compensation		—		—		14,941			—			—			—			—			—			14,941
Treasury stock purchases		—		—		—			—			—			(1,485	)		(112,803	)		—			(112,803	)
Excise taxes on treasury stock purchases		—		—		—			—			—			—			(972	)		—			(972	)
Total comprehensive income, net of taxes		—		—		—			18,153			222,935			—			—			(30	)		241,058
Return of investment to noncontrolling interests		—		—		—			—			—			—			—			(1,015	)		(1,015	)
Balance at December 31, 2023		65,472	$	6,547	$	863,963		$	35,006		$	2,691,665			(6,843	)	$	(411,750	)	$	1,246		$	3,186,677

See accompanying notes to consolidated financial statements.

56

KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(1) Summary of Significant Accounting Policies

Principles of Consolidation. The consolidated financial statements include the accounts of Kirby Corporation and all majority-owned subsidiaries (the “Company”). All investments in which the Company owns 20% to 50% and exercises significant influence over operating and financial policies are accounted for using the equity method. All material intercompany accounts and transactions have been eliminated in consolidation. Certain reclassifications have been made to reflect the current presentation of financial information. Such reclassifications have no impact on previously reported net earnings (loss), stockholders’ equity, or cash flows.

Accounting Policies

Cash Equivalents. Cash equivalents consist of all short-term, highly liquid investments with maturities of three months or less at date of purchase.

Accounts Receivable. In the normal course of business, the Company extends credit to its customers. The Company regularly reviews the accounts and makes adequate provisions for probable uncollectible balances. It is the Company’s opinion that the accounts have no impairment, other than that for which provisions have been made. Included in accounts receivable-trade as of December 31, 2023 and 2022 were $136.3 million and $139.5 million, respectively, of accruals for revenues earned which have not been invoiced as of the end of each year.

Accrued Insurance. The Company’s marine transportation and distribution and services operations are subject to hazards associated with such businesses. The marine transportation business in particular is subject to property damage and casualty risks associated with operating vessels carrying large volumes of bulk liquid and dry cargo in a marine environment. The Company maintains insurance coverage against these hazards with insurance companies subject to a deductible, below which the Company is liable. The Company uses historic experience and actuarial analysis by outside consultants to estimate an appropriate level of accrued insurance liabilities including estimates on individual claims outstanding and an estimated amount for losses that may have occurred but have not been reported to the Company (“IBNR”) or not yet fully developed. If the actual number of claims and magnitude were substantially greater than assumed, the required level of accrued liabilities for claims incurred but not reported or fully developed could be materially understated. Insurance premiums, IBNR losses and incurred claim losses, up to the Company’s deductible for the years ended December 31, 2023, 2022, and 2021, were $52.5 million, $39.1 million, and $37.8 million, respectively.

The Company records receivables from its insurers for incurred claims above the Company’s deductible. If the solvency of the insurers becomes impaired, there could be an adverse impact on the accrued receivables and the availability of insurance. Included in accounts receivable-other as of December 31, 2023 and 2022 were $29.6 million and $27.7 million, respectively, of receivables from insurance companies to cover claims in excess of the Company’s deductible.

Concentrations of Credit Risk. Financial instruments which potentially subject the Company to concentrations of credit risk are primarily trade accounts receivables. The Company’s marine transportation customers include the major oil refining and petrochemical companies. The distribution and services customers are oilfield service companies, oil and gas operators and producers, on-highway transportation companies, marine transportation companies, commercial fishing companies, construction companies, power generation companies, and the United States government. The Company regularly reviews its accounts and estimates the amount of uncollectible receivables each period and establishes an allowance for uncollectible amounts. The amount of the allowance is based on the age of unpaid amounts, information about the current financial strength of customers, and other relevant information. Estimates of uncollectible amounts are revised each period, and changes are recorded in the period they become known.

Historically, credit risk with respect to these trade receivables has generally been considered minimal because of the financial strength of the Company’s customers; however, a United States or global recession or other adverse economic condition could impact the collectability of certain customers’ trade receivables which could have a material effect on the Company’s results of operations.

Inventories. Inventories are stated at the lower of average cost or net realizable value.

Property, Maintenance and Repairs. Property is recorded at cost or acquisition date fair value; improvements and betterments are capitalized as incurred. Depreciation is recorded using the straight-line method over the estimated useful lives of the individual assets as follows: marine transportation equipment, 5-40 years; buildings, 10-40 years; other equipment, 2-10 years; and leasehold improvements, term of lease. When property items are retired, sold, or otherwise disposed of, the related cost and accumulated depreciation are removed from the accounts with any gain or loss on the disposition included in the statement of earnings. Maintenance and repairs on vessels built for use on the inland waterways are charged to operating expense as incurred and includes the costs incurred

57

in United States Coast Guard (“USCG”) inspections unless the shipyard extends the life, improves the operating capacity, or replaces significant components of the vessel, which results in the costs being capitalized.

The following table summarizes the balances of property and equipment – net (in thousands):

	December 31,
	2023			2022
Land	$	39,567		$	38,551
Marine transportation equipment		5,029,653			4,837,379
Buildings and other equipment		641,871			505,942
Construction in progress		112,947			70,271
	$	5,824,038		$	5,452,143
Accumulated depreciation		(1,962,933	)		(1,818,681	)
Property and equipment – net	$	3,861,105		$	3,633,462

Drydocking on Ocean-Going Vessels. The Company’s ocean-going vessels are subject to regulatory drydocking requirements after certain periods of time to be inspected, have planned major maintenance performed and be recertified by the American Bureau of Shipping (“ABS”). These recertifications generally occur twice in a five-year period. The Company defers the drydocking expenditures incurred on its ocean-going vessels due to regulatory marine inspections by the ABS and amortizes the costs of the shipyard over the period between drydockings, generally 30 or 60 months, depending on the type of major maintenance performed. Drydocking expenditures that extend the life, improve the operating capability, or replace significant components of the vessel are capitalized. The Company recognized amortization of major maintenance costs of $29.0 million, $29.0 million, and $33.2 million for the years ended December 31, 2023, 2022, and 2021, respectively, in costs of sales and operating expenses. Routine repairs and maintenance on ocean-going vessels are expensed as incurred. Interest is capitalized on the construction of new ocean-going vessels. For the years ended December 31, 2023, 2022 and 2021, no interest was capitalized.

Environmental Liabilities. The Company expenses costs related to environmental events as they are incurred or when a loss is considered probable and reasonably estimable.

Goodwill. The excess of the purchase price over the fair value of identifiable net assets acquired in transactions accounted for as a purchase is included in goodwill. The Company conducted its annual goodwill impairment tests at November 30, 2023, 2022, and 2021. The Company also conducted an interim goodwill impairment test at September 30, 2021. Refer to Note 7, Impairments and other charges for more information. The Company will continue to conduct goodwill impairment tests as of November 30 of subsequent years, or whenever events or circumstances indicate that interim impairment testing is necessary. The amount of goodwill impairment, if any, is typically measured based on a combination of projected discounted future operating cash flows using an appropriate discount rate and a market approach for comparable companies. The following table summarizes the changes in goodwill (in thousands):

	Marine Transportation			Distribution and Services			Total
Balance at December 31, 2022 (gross)		505,784			560,155			1,065,939
Accumulated impairment and amortization		(237,626	)		(389,565	)		(627,191	)
Balance at December 31, 2022 and 2023	$	268,158		$	170,590		$	438,748

Other Intangibles. Other intangibles include assets for favorable contracts and customer relationships, distributorship and dealership agreements, trade names and non-compete agreements and liabilities for unfavorable leases and contracts. The following table summarizes the balances of other intangible assets and other intangible liabilities (in thousands):

	December 31,
	2023			2022
Other intangible assets – gross	$	184,622		$	203,242
Accumulated amortization		(141,695	)		(151,779	)
Other intangible assets – net	$	42,927		$	51,463
Other intangible liabilities – gross	$	8,800		$	13,860
Accumulated amortization		(8,800	)		(13,280	)
Other intangible liabilities – net	$	—		$	580

The costs of intangible assets and liabilities are amortized to expense in a systematic and rational manner over their estimated useful lives. For the years ended December 31, 2023, 2022, and 2021, the amortization expense for intangibles was $8.1 million, $7.6 million, and $7.8 million, respectively. Estimated net amortization expense for amortizable intangible assets and liabilities for the next five years

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(2024 – 2028) is approximately $8.5 million, $8.5 million, $6.3 million, $5.0 million, and $3.5 million, respectively, and $11.1 million thereafter. As of December 31, 2023, the weighted average amortization period for intangible assets and liabilities was approximately seven years.

Revenue Recognition. The majority of marine transportation revenue is derived from term contracts, ranging from one to three years, some of which have renewal options, and the remainder is from spot contracts. The majority of the term contracts by revenue are for terms of one year. The Company provides marine transportation services for its customers and, in almost all cases, does not assume ownership of the products it transports. The Company enters into agreements with its customers to transport cargo from a designated origin to a designated destination at a set rate (affreightment) or at a daily rate (time charter). The rate may or may not escalate during the term of the contract, however, the base rate generally remains constant and contracts often include escalation provisions to recover changes in specific costs such as fuel. Time charter or contracts of affreightment of one year or greater are considered term contract revenues and agreements of less than a year are included in spot contract revenues. Spot contracts typically involve an agreement with a customer to move cargo from a specific origin to a designated destination for a rate generally negotiated at the time the cargo movement takes place. Spot contract rates are typically at the current “market” rate, including fuel, and are subject to market volatility. The Company uses a voyage accounting method of revenue recognition for its marine transportation revenues which allocates voyage revenue based on the percent of the voyage completed during the period. The performance of the service is invoiced as the transaction occurs and payment is required depending on each specific customer’s credit.

Distribution products and services are generally sold based upon purchase orders or preferential service agreements with the customer that include fixed or determinable prices. Parts sales are recognized when control transfers to the customer, generally when title passes upon shipment to customers. Service revenue is recognized over time as the service is provided using measures of progress utilizing hours worked or costs incurred as a percentage of estimated hours or expected costs. Revenue from rental agreements is generally recognized on a straight-line basis over the rental period. The Company recognizes the revenues on manufacturing activities upon shipment and transfer of control to the customer. The transactions in the distribution and services segment (“KDS”) are typically invoiced as parts are shipped or upon the completion of the service job. Contract manufacturing activities are generally invoiced upon shipment and the Company will often get deposits from its customers prior to starting work, or progress payments during the project depending on the credit worthiness of the customer and the size of the project.

Stock-Based Compensation. The Company has share-based compensation plans covering selected officers and other key employees as well as the Company’s Board of Directors. Stock-based grants made under the Company’s stock plans are measured at fair value on the date of the grant and the cost for all grants made under the director plan and for grants made under the employee plan is generally recognized ratably over the vesting period of the restricted stock unit (“RSU”), stock option, or restricted stock. The employee plan, however, includes a provision for the continued vesting of unvested stock options and RSUs for employees who meet certain years of service and age requirements at the time of their retirement. The provision results in shorter expense accrual periods on stock options and RSUs granted to employees who are nearing retirement and meet the service and age requirements. Stock option grants are valued at the date of grant as calculated under the Black-Scholes option pricing model. The Company accounts for forfeitures as they occur. The Company’s stock-based compensation plans are more fully described in Note 8, Stock Award Plans.

Taxes on Income. The Company follows the asset and liability method of accounting for income taxes. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

Treasury Stock. The Company follows the average cost method of accounting for treasury stock transactions.

Impairment of Long-lived Assets and for Long-lived Assets to Be Disposed Of. The Company performs an impairment assessment whenever events or changes in circumstances indicate that the carrying amount of long-lived assets may not be recoverable.

Recoverability on marine transportation assets is assessed based on vessel classes, not on individual assets, because identifiable cash flows for individual marine transportation assets are not available. Projecting customer contract volumes allows estimation of future cash flows by projecting pricing and utilization by vessel class but it is not practical to project which individual marine transportation asset will be utilized for any given contract. Because customers generally do not specify which particular vessel is used, prices are quoted based on vessel classes not individual assets. Nominations of vessels for specific jobs are determined on a day by day basis and are a function of the equipment class required and the geographic position of vessels within that class at that particular time as vessels within a class are interchangeable and provide the same service. The Company’s vessels are mobile assets and equipped to operate in geographic regions throughout the United States and the Company has in the past and expects to continue to move vessels from one region to another when it is necessary due to changing markets and it is economical to do so. Barge vessel classes are based on similar capacities, hull type, and type of product and towing vessels are based on similar hull type and horsepower.

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If a triggering event is identified, the Company compares the carrying amount of the asset group to the estimated undiscounted future cash flows expected to result from the use of the asset group. If the carrying amount of the asset group exceeds the estimated undiscounted future cash flows, the Company measures the amount of the impairment by comparing the carrying amount of the asset group to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell.

Fair Value Measurements. The accounting guidance for using fair value to measure certain assets and liabilities establishes a three tier value hierarchy, which prioritizes the inputs to valuation techniques used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little, if any, market data exists, therefore requiring an entity to develop its own assumptions about the assumptions that market participants would use in pricing the asset or liability. The fair value of the Company’s debt instruments is described in Note 5, Long-Term Debt.

Accounting Standards

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”) which requires entities to disclose additional information in specified categories with respect to the reconciliation of the effective tax rate to the statutory rate for federal, state, and foreign income taxes. ASU 2023-09 is effective for annual and interim periods beginning after December 15, 2023, with early adoption permitted. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements.

In November 2023, the FASB issued ASU No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”) to improve reportable segment disclosure requirements. The amendments require disclosure of significant segment expenses regularly provided to the chief operating decision maker (“CODM”) as well as other segment items, extend certain annual disclosures to interim periods, clarify the applicability to single reportable segment entities, permit more than one measure of profit or loss to be reported under certain conditions, and require disclosure of the title and position of the CODM. ASU 2023-07 is effective for annual periods beginning after December 15, 2024 and for interim periods beginning after December 15, 2025, with early adoption permitted. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements.

(2) Acquisitions

On July 14, 2023, the Company purchased 23 inland tank barges with a total capacity of 265,000 barrels from an undisclosed seller for $37 million in cash. The 23 tank barges transport petrochemicals and refined products on the Mississippi River System and the Gulf Intracoastal Waterway. The average age of the 23 barges was 14 years.

The Company purchased four inland tank barges from a leasing company for $0.5 million in cash during the 2023 third quarter. The Company had been leasing the barges prior to the purchase.

On March 31, 2022, the Company paid $3.9 million in cash to purchase assets of a gearbox repair company in KDS. Assets acquired consisted primarily of property and equipment.

The Company purchased four inland tank barges from a leasing company for $7.5 million in cash during 2021. The Company had been leasing the barges prior to the purchase.

On October 4, 2021, the Company paid $1.6 million in cash to purchase assets of an energy storage systems manufacturer based in Texas which have been key to the development of new power generation solutions for electric fracturing equipment. Assets acquired and liabilities assumed consisted primarily of a right of use lease asset and lease liability for an operating lease assumed as part of the acquisition.

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(3) Revenues

The following table sets forth the Company’s revenues by major source (in thousands):

	Year Ended December 31,
	2023		2022		2021
Marine transportation segment:
Inland transportation	$	1,416,483	$	1,277,010	$	1,005,145
Coastal transportation		305,454		339,957		317,773
	$	1,721,937	$	1,616,967	$	1,322,918
Distribution and services segment:
Commercial and industrial	$	802,474	$	651,566	$	578,011
Oil and gas		567,229		516,221		345,731
	$	1,369,703	$	1,167,787	$	923,742

The Company’s revenue is measured based on consideration specified in its contracts with its customers. The Company recognizes revenue over time as it provides services to its customers, or at the point in time that control over a part or product transfers to its customer.

Contract Assets and Liabilities. Contract liabilities represent advance consideration received from customers, and are recognized as revenue over time or at a point in time as the related performance obligation is satisfied. Revenues recognized during the years ended December 31, 2023, 2022, and 2021, that were included in the opening contract liability balances were $84.0 million, $61.7 million and $40.9 million, respectively. The Company has recognized all contract liabilities within the deferred revenues financial statement caption on the balance sheet. The Company did not have any contract assets at December 31, 2023 or December 31, 2022. The Company applies the practical expedient that allows non-disclosure of information about remaining performance obligations that have original expected durations of one year or less.

(4) Segment Data

The Company’s operations are aggregated into two reportable business segments as follows:

Marine Transportation — Provides marine transportation by United States flagged vessels principally of liquid cargoes throughout the United States inland waterway system, along all three United States coasts, and to a lesser extent, in United States coastal transportation of dry-bulk cargoes. The principal products transported include petrochemicals, black oil, refined petroleum products and agricultural chemicals.

Distribution and Services — Provides after-market services and genuine replacement parts for engines, transmissions, reduction gears and related equipment used in oilfield services, marine, power generation, on-highway, and other industrial applications. The Company also rents equipment including generators, industrial compressors, high capacity lift trucks, and refrigeration trailers for use in a variety of industrial markets, and manufactures and remanufactures oilfield service equipment, including pressure pumping units, electric power generation equipment, specialized electrical distribution and control equipment, and high capacity energy storage/battery systems for oilfield service and railroad customers.

The Company’s two reportable business segments are managed separately based on fundamental differences in their operations. The Company’s accounting policies for the business segments are the same as those described in Note 1, Summary of Significant Accounting Policies. The Company evaluates the performance of its segments based on the contributions to operating income of the respective segments, and before income taxes, interest, gains or losses on disposition of assets, other nonoperating income, noncontrolling interests, accounting changes, and nonrecurring items. Intersegment revenues, based on market-based pricing, of KDS from KMT of $39.8 million, $31.9 million, and $23.6 million in 2023, 2022, and 2021, respectively, as well as the related intersegment profit of $4.0 million, $3.2 million, and $2.4 million in 2023, 2022, and 2021, respectively, have been eliminated from the tables below.

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The following tables set forth by reportable segment the revenues, profit or loss, total assets, depreciation and amortization, and capital expenditures attributable to the principal activities of the Company (in thousands):

	Year Ended December 31,
	2023			2022			2021
Revenues:
Marine transportation	$	1,721,937		$	1,616,967		$	1,322,918
Distribution and services		1,369,703			1,167,787			923,742
	$	3,091,640		$	2,784,754		$	2,246,660
Segment profit (loss):
Marine transportation	$	238,943		$	136,184		$	63,015
Distribution and services		114,481			67,037			27,607
Other		(59,299	)		(38,246	)		(381,223	)
	$	294,125		$	164,975		$	(290,601	)
Depreciation and amortization:
Marine transportation	$	184,225		$	177,551		$	185,979
Distribution and services		19,842			16,776			20,573
Other		7,089			7,116			7,166
	$	211,156		$	201,443		$	213,718
Capital expenditures:
Marine transportation	$	255,411		$	147,170		$	84,353
Distribution and services		140,769			21,713			8,104
Other		5,550			3,723			5,558
	$	401,730		$	172,606		$	98,015

	December 31,
	2023		2022
Total assets:
Marine transportation	$	4,454,931	$	4,285,647
Distribution and services		1,156,384		1,041,841
Other		110,882		227,436
	$	5,722,197	$	5,554,924

The following table presents the details of “Other” segment profit (loss) (in thousands):

	Year Ended December 31,
	2023			2022			2021
General corporate expenses	$	(23,341	)	$	(18,614	)	$	(13,803	)
Gain on disposition of assets		5,009			8,279			5,761
Impairments and other charges		—			—			(340,713	)
Interest expense		(52,008	)		(44,588	)		(42,469	)
Other income		11,041			16,677			10,001
	$	(59,299	)	$	(38,246	)	$	(381,223	)

The following table presents the details of “Other” total assets (in thousands):

	December 31,
	2023		2022
General corporate assets	$	108,306	$	225,265
Investment in affiliates		2,576		2,171
	$	110,882	$	227,436

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(5) Long-Term Debt

The following table presents the carrying value and fair value (determined using inputs characteristic of a Level 2 fair value measurement) of debt outstanding (in thousands):

	December 31,
	2023					2022
	Carrying Value			Fair Value		Carrying Value			Fair Value
Revolving Credit Facility due July 29, 2027 (a)	$	44,000		$	44,000	$	—		$	—
Term Loan due July 29, 2027 (a)		170,000			170,000		170,000			170,000
3.29% senior notes due February 27, 2023		—			—		350,000			352,275
4.2% senior notes due March 1, 2028		500,000			475,920		500,000			477,660
3.46% senior notes due January 19, 2033		60,000			49,955		60,000			42,647
3.51% senior notes due January 19, 2033		240,000			200,698		—			—
Credit Line due June 30, 2024		—			—		—			—
Bank notes payable		8,068			8,068		3,292			3,292
		1,022,068			948,641		1,083,292			1,045,874
Unamortized debt discounts and issuance costs (b)		(5,473	)		—		(3,674	)		—
	$	1,016,595		$	948,641	$	1,079,618		$	1,045,874

(a)Variable interest rate of 6.8% and 5.8% at December 31, 2023 and 2022, respectively.

(b)Excludes $1.8 million attributable to the 2027 Revolving Credit Facility included in other assets at December 31, 2022.

The aggregate payments due on the long-term debt in each of the next five years were as follows (in thousands):

2024	$	8,068
2025		32,500
2026		56,250
2027		125,250
2028		500,000
Thereafter		300,000
	$	1,022,068

At the beginning of 2022, the Company had an amended and restated credit agreement (the “2024 Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank, that allowed for an $850 million unsecured revolving credit facility (the “2024 Revolving Credit Facility”) and an unsecured term loan (the “2024 Term Loan”) with a maturity date of March 27, 2024. The 2024 Term Loan was prepayable, in whole or in part, without penalty.

On July 29, 2022, the Company entered into a new credit agreement (the “2027 Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank that allows for a $500 million unsecured revolving credit facility (the “2027 Revolving Credit Facility”) and a $250 million unsecured term loan (the “2027 Term Loan”) with a maturity date of July 29, 2027. The 2027 Credit Agreement replaced the 2024 Credit Agreement. In conjunction with entering into the 2027 Credit Agreement, on July 29, 2022, the Company borrowed $35 million under the 2027 Revolving Credit Facility and $250 million under the 2027 Term Loan to repay borrowings under the 2024 Term Loan. In the fourth quarter of 2022, the Company repaid $80.0 million under the 2027 Term Loan prior to scheduled maturities. As a result, no repayments are required until June 30, 2025. Outstanding letters of credit under the 2027 Revolving Credit Facility were $6,000 and available borrowing capacity was $456.0 million as of December 31, 2023.

The 2027 Term Loan is repayable in quarterly installments, with no repayments until June 30, 2025, in increasing percentages of the original principal amount of the loan, with the remaining unpaid balance of approximately $43.8 million payable upon maturity, assuming no prepayment. The 2027 Term Loan is prepayable, in whole or in part, without penalty. The 2027 Credit Agreement provides for a variable interest rate based on the Secured Overnight Financing Rate (“SOFR”) or a base rate calculated with reference to the prime rate quoted by The Wall Street Journal, the Federal Reserve Bank of New York Rate plus 0.5%, or the adjusted SOFR rate for a one month interest period plus 1.0%, among other factors (the “Alternate Base Rate”). The interest rate varies with the Company’s credit rating and is currently 137.5 basis points over SOFR or 37.5 basis points over the Alternate Base Rate. The 2027 Credit Agreement contains certain financial covenants including an interest coverage ratio and debt-to-capitalization ratio. In addition to financial covenants, the 2027 Credit Agreement contains covenants that, subject to exceptions, restrict debt incurrence, mergers and acquisitions, sales of assets, dividends and investments, liquidations and dissolutions, capital leases, transactions with affiliates, and changes in lines of business. The 2027 Credit Agreement specifies certain events of default, upon the occurrence of which the maturity of the outstanding loans may be accelerated, including the failure to pay principal or interest, violation of covenants and default on other indebtedness,

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among other events. Borrowings under the 2027 Credit Agreement may be used for general corporate purposes including acquisitions. The 2027 Revolving Credit Facility includes a $25 million commitment which may be used for standby letters of credit.

The Company has $500 million of 4.2% senior unsecured notes due March 1, 2028 (the “2028 Notes”) with U.S. Bank National Association, as trustee. No principal payments are required until maturity. Interest payments of $10.5 million are due semi-annually on March 1 and September 1 of each year. The 2028 Notes are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. The 2028 Notes contain certain covenants on the part of the Company, including covenants relating to liens, sale-leasebacks, asset sales and mergers, among others. The 2028 Notes also specify certain events of default, upon the occurrence of which the maturity of the notes may be accelerated, including failure to pay principal and interest, violation of covenants or default on other indebtedness, among others.

On February 3, 2022, the Company entered into a note purchase agreement for the issuance of $300 million of unsecured senior notes with a group of institutional investors, consisting of $60 million of 3.46% series A notes (“Series A Notes”) and $240 million of 3.51% series B notes (“Series B Notes”), each due January 19, 2033 (collectively, the “2033 Notes”). The Series A Notes were issued on October 20, 2022, and the Series B Notes were issued on January 19, 2023. No principal payments will be required until maturity. Beginning in 2023, interest payments of $5.3 million are due semi-annually on January 19 and July 19 of each year, with the exception of the first payment on January 19, 2023, which was $0.5 million. The 2033 Notes are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. The 2033 Notes contain certain covenants on the part of the Company, including an interest coverage covenant, a debt-to-capitalization covenant, and covenants relating to liens, asset sales and mergers, among others. The 2033 Notes also specify certain events of default, upon the occurrence of which the maturity of the notes may be accelerated, including failure to pay principal and interest, violation of covenants or default on other indebtedness, among others. The 3.29% unsecured senior notes due February 27, 2023 (the “2023 Notes”) were repaid using a combination of the proceeds from the issuance of the 2033 Notes and availability under the 2027 Revolving Credit Facility.

The Company has a $10.0 million line of credit (“Credit Line”) with Bank of America, N.A. (“Bank of America”) for short-term liquidity needs and letters of credit, with a maturity date of June 30, 2024. The Credit Line allows the Company to borrow at an interest rate agreed to by Bank of America and the Company at the time each borrowing is made or continued. The Company had no borrowings outstanding under the Credit Line as of December 31, 2023. Outstanding letters of credit under the Credit Line were $7.3 million and available borrowing capacity was $2.7 million as of December 31, 2023.

The Company also had $8.1 million and $3.3 million of short-term unsecured loans outstanding, as of December 31, 2023 and 2022, respectively, related to its Colombia operations.

As of December 31, 2023, the Company was in compliance with all covenants under its debt instruments.

(6) Leases

The Company currently leases various facilities and equipment under cancelable and noncancelable operating leases. The accounting for the Company’s leases may require judgments, which include determining whether a contract contains a lease, allocating the consideration between lease and non-lease components, and determining the incremental borrowing rates. Leases with an initial noncancelable term of 12 months or less are not recorded on the balance sheet and the related lease expense is recognized on a straight-line basis over the lease term. The Company has also elected to combine lease and non-lease components on all classes of leased assets, except for leased towing vessels for which the Company estimates approximately 70% of the costs relate to service costs and other non-lease components. Variable lease costs relate primarily to real estate executory costs (i.e. taxes, insurance and maintenance).

Future minimum lease payments under operating leases that have initial noncancelable lease terms in excess of one year were as follows (in thousands):

2024	$	38,943
2025		27,638
2026		24,945
2027		22,842
2028		18,318
Thereafter		79,755
Total lease payments		212,441
Less: imputed interest		(40,290	)
Operating lease liabilities	$	172,151

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The following table summarizes lease costs (in thousands):

	Year Ended December 31,
	2023			2022			2021
Operating lease cost	$	42,821		$	42,319		$	40,786
Variable lease cost		2,376			1,780			1,793
Short-term lease cost		30,005			25,365			17,914
Sublease income		(3,223	)		(305	)		(1,032	)
Total lease cost	$	71,979		$	69,159		$	59,461

The following table summarizes other supplemental information about the Company’s operating leases:

	December 31,
	2023			2022			2021
Weighted average discount rate		4.4	%		4.1	%		3.8	%
Weighted average remaining lease term	9 years			9 years			9 years

(7) Impairments and Other Charges

During the third quarter of 2021, the Company decided to exit the Hawaii marine transportation market, selling marine transportation equipment including four coastal tank barges, seven coastal tugboats, and certain other assets for aggregate cash proceeds of $17.2 million. In addition, as of September 30, 2021, the Company retired and classified as held for sale, an additional 12 coastal tank barges and four coastal tugboats which were underutilized. The sales and retirements of coastal marine transportation equipment resulted in an aggregate non‑cash impairment charge of $97.5 million to reduce the carrying value of these assets to their estimated sales prices, net of costs to sell.

As a result of the sale of the Hawaii marine transportation equipment, and the decision to retire certain additional underutilized coastal tank barges and tugboats, the Company concluded that a triggering event had occurred and performed interim quantitative impairment tests as of September 30, 2021 for certain of KMT’s long-lived assets and goodwill within the coastal marine market.

The Company determined the estimated fair value of such long-lived assets using a combination of a cost approach, a discounted cash flow analysis, and a market approach. The Company determined the estimated fair value of the reporting unit using a combination of a discounted cash flow analysis and a market approach for comparable companies. These analyses included management’s judgment regarding short-term and long-term internal forecasts, updated for recent events, appropriate discount rates, and capital expenditures using inputs characteristic of a Level 3 fair value measurement.

In performing the impairment test of certain long-lived assets within KMT, the Company determined that the carrying value of certain long-lived assets, including certain coastal marine transportation equipment and operating lease right-of-use assets, were no longer recoverable, resulting in a non-cash impairment charge of $24.2 million during the three months ended September 30, 2021 to reduce such long-lived assets to fair value.

Based upon the results of the goodwill impairment test, the Company concluded that the carrying value of one reporting unit in KMT exceeded its estimated fair value. The carrying value of the reporting unit, including goodwill, and after recording impairments of long-lived assets identified above, exceeded its estimated fair value, resulting in a non-cash goodwill impairment charge of $219.1 million for the three months ended September 30, 2021.

(8) Stock Award Plans

The Company has share-based compensation plans which are described below. The compensation cost that has been charged against earnings for the Company’s stock award plans and the income tax benefit recognized in the statement of earnings for stock awards were as follows (in thousands):

	Year Ended December 31,
	2023		2022		2021
Compensation cost	$	14,941	$	13,865	$	15,713
Income tax benefit	$	3,616	$	3,533	$	4,410

The Company has an employee stock award plan for selected officers and other key employees which provides for the issuance of RSUs, stock options, restricted stock awards, and performance awards. Restricted stock and RSUs generally vest ratably over five years, however, the plan includes a provision for the continued vesting of unvested stock options and RSUs for employees who meet certain

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years of service and age requirements at the time of their retirement. The provision results in shorter expense accrual periods on stock options and RSUs granted to employees who are nearing retirement and meet the service and age requirements. At December 31, 2023, there were 2,045,694 shares available for future grants under the Plan.

The exercise price for each option equals the fair market value per share of the Company’s common stock on the date of grant. Substantially all stock options outstanding under the plan have terms of seven years and vest ratably over three years. No performance awards payable in stock have been awarded under the plan and no outstanding stock options under the employee plan were issued with stock appreciation rights.

The following is a summary of the stock option activity under the employee plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		396,165		$	70.06
Exercised		(117,896	)	$	60.84
Expired		(23,024	)	$	73.66
Outstanding at December 31, 2023		255,245		$	74.00

The following table summarizes information about the Company’s outstanding and exercisable stock options under the employee plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)
$64.89		15,500		1.3	$	64.89				15,500	$	64.89
$73.29 – $75.50		233,040		2.1	$	74.29				233,040	$	74.29
$84.90		6,705		2.3	$	84.90				6,705	$	84.90
$64.89 – $84.90		255,245		2.0	$	74.00	$	1,187		255,245	$	74.00	$	1,187

There were no unvested restricted stock awards under the employee plan at December 31, 2023 and 2022 and no restricted stock awards were granted under the employee plan during 2023, 2022, and 2021.

The following is a summary of RSU activity under the employee plan described above:

	Unvested RSUs			Weighted Average Grant Date Fair Value Per Unit
Nonvested balance at December 31, 2022		558,819		$	62.13
Granted		184,440		$	72.23
Vested		(161,550	)	$	64.85
Forfeited		(27,105	)	$	63.68
Nonvested balance at December 31, 2023		554,604		$	64.61

The weighted average grant date fair value of RSUs granted for the years ended December 31, 2023, 2022, and 2021 was $72.23, $66.13, and $51.36, respectively.

During February 2024, the Company granted 164,793 RSUs to selected officers and other key employees under its employee stock award plan, which substantially all vest ratably over five years.

The Company has a stock award plan for nonemployee directors of the Company which provides for the issuance of stock options and restricted stock. The director plan provides for automatic grants of restricted stock to nonemployee directors after each annual meeting of stockholders. In addition, the director plan allows for the issuance of stock options or restricted stock in lieu of cash for all or part of the annual director fee at the option of the director. The exercise prices for all options granted under the plan are equal to the fair market value per share of the Company’s common stock on the date of grant. The terms of the options are ten years. The restricted

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stock issued after each annual meeting of stockholders vests six months after the date of grant. Options granted and restricted stock issued in lieu of cash director fees vest in equal quarterly increments during the year to which they relate. At December 31, 2023, 369,360 shares were available for future grants under the director plan. The director stock award plan is intended as an incentive to attract and retain qualified independent directors.

The following is a summary of the stock option activity under the director plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		56,480		$	86.19
Granted		3,865		$	72.83
Exercised		—		$	—
Expired		(30,000	)	$	80.04
Outstanding at December 31, 2023		30,345		$	90.57

The following table summarizes information about the Company’s outstanding and exercisable stock options under the director plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)
$70.65 – $73.57		7,053		6.6	$	71.85				6,278	$	71.75
$84.90 – $85.30		5,292		4.8	$	85.10				5,292	$	85.10
$99.52		18,000		0.3	$	99.52				18,000	$	99.52
$70.65 – $99.52		30,345		2.6	$	90.57	$	47		29,570	$	91.04	$	42

The following is a summary of the restricted stock award activity under the director plan described above:

	Unvested Restricted Stock Award Shares			Weighted Average Grant Date Fair Value Per Share
Nonvested balance at December 31, 2022		1,698		$	65.36
Granted		31,526		$	72.67
Vested		(32,604	)	$	72.29
Nonvested balance at December 31, 2023		620		$	72.65

The weighted average grant date fair value of restricted stock awards granted under the director plan for the years ended December 31, 2023, 2022, and 2021 were $72.67, $64.61, and $65.13, respectively.

The total intrinsic value of all stock options exercised under all of the Company’s plans was $1.5 million, $0.4 million, and $0.1 million for the years ended December 31, 2023, 2022, and 2021, respectively.

The total fair value of all the restricted stock vestings under all of the Company’s plans was $2.5 million, $3.2 million, and $5.3 million for the years ended December 31, 2023, 2022, and 2021, respectively. The actual tax benefit realized for tax deductions from restricted stock vestings was $0.6 million, $0.8 million, and $1.5 million for the years ended December 31, 2023, 2022, and 2021, respectively.

The total fair value of all the RSU vestings under the Company’s employee plan was $10.9 million, $9.5 million, and $4.4 million for the years ended December 31, 2023, 2022, and 2021, respectively. The actual tax benefit realized for tax deductions from RSU vestings was $2.6 million, $2.4 million, and $1.2 million for the years ended December 31, 2023, 2022, and 2021, respectively.

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As of December 31, 2023, there was $45,000 of unrecognized compensation cost related to restricted stock and $15.3 million related to nonvested RSUs. The restricted stock is expected to be recognized over a weighted average period of approximately 0.2 years and RSUs over approximately 2.7 years.

There were no stock options granted under the employee plan during the years ended December 31, 2023, 2022, and 2021. The weighted average per share fair value of stock options granted under the director plan during the year ended December 31, 2023 was $32.33 and the fair value of the stock options was $0.1 million. There were no stock options granted under the director plan during the years ended December 31, 2022 and 2021. The Company currently uses treasury stock shares for restricted stock grants, RSU vestings, and stock option exercises. The fair value of each stock option was determined using the Black-Scholes option pricing model.

The key input variables used in valuing the stock options granted were as follows:

	Year Ended December 31,
	2023
Dividend yield	None
Average risk-free interest rate		3.7	%
Stock price volatility		35	%
Estimated option term	7 years

(9) Taxes on Income

Earnings (loss) before taxes on income and details of the provision (benefit) for taxes on income were as follows (in thousands):

	Year Ended December 31,
	2023			2022		2021
Earnings (loss) before taxes on income:
United States	$	293,011		$	164,590	$	(290,181	)
Foreign		1,114			385		(420	)
	$	294,125		$	164,975	$	(290,601	)
Provision (benefit) for taxes on income:
U.S. Federal:
Current	$	(41	)	$	513	$	(460	)
Deferred		61,205			34,980		(48,843	)
	$	61,164		$	35,493	$	(49,303	)
U.S. State:
Current	$	5,498		$	3,793	$	1,560
Deferred		4,093			2,802		4,424
	$	9,591		$	6,595	$	5,984
Foreign:
Current	$	465		$	126	$	(511	)
	$	465		$	126	$	(511	)
Consolidated:
Current	$	5,922		$	4,432	$	589
Deferred		65,298			37,782		(44,419	)
	$	71,220		$	42,214	$	(43,830	)

On November 13, 2021, the voters of the state of Louisiana approved a constitutional amendment that removed the corporate tax deduction for federal income taxes paid and lowered the corporate income tax rate from 8% to 7.5% effective January 1, 2022. The result of the amendment was an increase in the effective Louisiana state income tax rate, net of deduction for federal income tax, from 6.3% to 7.5%. As a result of the amendment, the Company recognized a one-time deferred tax provision of $5.7 million during the fourth quarter of 2021 due to remeasuring the Company’s Louisiana and U.S. deferred tax assets and liabilities based on the new effective Louisiana state income tax rate.

During 2021, the Company received a tax refund of $119.5 million, including accrued interest, for its 2019 tax return related to net operating losses being carried back to offset taxable income generated between 2014 and 2017.

At December 31, 2022, the Company had a federal income tax receivable of $70.4 million, included in Accounts Receivable – Other on the balance sheet. In April 2023, the Company received its tax refund of $70.4 million plus accrued interest.

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The Company’s provision (benefit) for taxes on income varied from the statutory federal income tax rate due to the following:

	Year Ended December 31,
	2023			2022			2021
United States income tax statutory rate		21.0	%		21.0	%		21.0	%
State and local taxes, net of federal benefit		2.6			3.1			(1.7	)
Other – net		0.6			1.5			(4.2	)
		24.2	%		25.6	%		15.1	%

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities were as follows (in thousands):

	December 31,
	2023			2022
Deferred tax assets:
Allowance for doubtful accounts	$	1,549		$	1,556
Inventory		10,500			11,679
Insurance accruals		6,077			4,856
Deferred compensation		11,441			7,703
Unrealized gain on defined benefit plans		(9,982	)		(5,532	)
Goodwill and other intangibles		39,719			52,847
Operating loss carryforwards		52,082			79,699
Retirement benefits		3,548			5,472
Other		13,467			9,962
		128,401			168,242
Valuation allowances		(22,073	)		(19,960	)
		106,328			148,282
Deferred tax liabilities:
Property		(695,233	)		(671,830	)
Deferred state taxes		(90,457	)		(87,445	)
Other		(17,195	)		(14,891	)
		(802,885	)		(774,166	)
	$	(696,557	)	$	(625,884	)

During 2023, the Company generated federal taxable income which was completely offset by federal net operating loss carryforwards. The Company had federal operating loss deferred tax assets of $19.8 million and $47.9 million at December 31, 2023 and 2022, respectively.

The Company had state operating loss deferred tax assets of $27.2 million and $26.6 million at December 31, 2023 and 2022, respectively. The valuation allowance for state deferred tax assets as of December 31, 2023 and 2022 was $17.0 million and $14.8 million, respectively, related to the Company’s state net operating loss carryforwards based on the Company’s determination that it is more likely than not that the deferred tax assets will not be realized. Expiration of these state net operating loss carryforwards vary by state through 2030 and none will expire in fiscal 2024.

As of December 31, 2023 and 2022, the Company had a Canadian net operating loss carryforward of $5.1 million which expires between 2037 and 2043. A full valuation allowance has been provided for this asset.

The Company or one of its subsidiaries files income tax returns in the United States federal jurisdiction and various state jurisdictions. During the first quarter of 2023, the Internal Revenue Service (“IRS”) communicated to the Company that it had completed its examination of the Company’s federal income tax returns for the years 2013 through 2020. With few exceptions, the Company and its subsidiaries’ state income tax returns are open to audit under the statute of limitations for the 2017 through 2022 tax years.

As of December 31, 2023, the Company has provided a liability of $0.8 million for unrecognized tax benefits related to various income tax issues which includes interest and penalties. The amount that would impact the Company’s effective tax rate, if recognized, is $0.7 million, with the difference between the total amount of unrecognized tax benefits and the amount that would impact the effective tax rate being primarily related to the federal tax benefit of state income tax items. It is not reasonably possible to determine if the liability for unrecognized tax benefits will significantly change prior to December 31, 2024 due to the uncertainty of possible examination results.

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A reconciliation of the beginning and ending amount of the liability for unrecognized tax benefits is as follows (in thousands):

	Year Ended December 31,
	2023			2022			2021
Balance at beginning of year	$	662		$	737		$	783
Additions based on tax positions related to the current year		—			13			13
Additions for tax positions of prior years		—			66			281
Reductions for tax positions of prior years		(14	)		(154	)		(340	)
Balance at end of year	$	648		$	662		$	737

The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes. The Company had $0.2 million of accrued liabilities for the payment of interest and penalties at both December 31, 2023 and 2022.

(10) Earnings Per Share

The following table presents the components of basic and diluted earnings (loss) per share (in thousands, except per share amounts):

	Year Ended December 31,
	2023			2022			2021
Net earnings (loss) attributable to Kirby	$	222,935		$	122,291		$	(246,954	)
Undistributed earnings allocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — basic		222,873			122,258			(246,954	)
Undistributed earnings allocated to restricted shares		62			33			—
Undistributed earnings reallocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — diluted	$	222,873		$	122,258		$	(246,954	)
Shares outstanding:
Weighted average common stock issued and outstanding		59,548			60,055			60,099
Weighted average unvested restricted stock		(17	)		(17	)		(46	)
Weighted average common stock outstanding — basic		59,531			60,038			60,053
Dilutive effect of stock options and restricted stock units		326			291			—
Weighted average common stock outstanding — diluted		59,857			60,329			60,053
Net earnings (loss) per share attributable to Kirby common stockholders:
Basic	$	3.74		$	2.04		$	(4.11	)
Diluted	$	3.72		$	2.03		$	(4.11	)

Diluted earnings per share was computed using the treasury stock method. Certain outstanding options to purchase approximately 33,000, 381,000, and 567,000 shares of common stock were excluded in the computation of diluted earnings per share as of December 31, 2023, 2022, and 2021, respectively, as such stock options would have been antidilutive. Certain outstanding RSUs to convert to 7,000 shares of common stock were also excluded in the computation of diluted earnings per share as of December 31, 2021 as such RSUs would have been antidilutive. No RSUs were antidilutive at December 31, 2023 and 2022.

(11) Inventories

The following table presents the details of inventories — net (in thousands):

	December 31,
	2023		2022
Finished goods	$	351,050	$	358,702
Work in process		103,339		103,146
	$	454,389	$	461,848

(12) Retirement Plans

The Company sponsors a defined benefit plan (the “Kirby Pension Plan”) for its inland vessel personnel and shore based tankermen. The plan benefits are based on an employee’s years of service and compensation. The plan assets consist primarily of equity and fixed income securities.

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On April 12, 2017, the Company amended the Kirby Pension Plan to cease all benefit accruals for periods after May 31, 2017 for certain participants. Participants grandfathered and not impacted were those, as of the close of business on May 31, 2017, who either (a) had completed 15 years of pension service or (b) had attained age 50 and completed 10 years of pension service. Participants non-grandfathered are eligible to receive discretionary 401(k) plan contributions.

On February 14, 2018, with the acquisition of Higman Marine, Inc. (“Higman”), the Company assumed Higman’s pension plan (the “Higman Pension Plan”) for its inland vessel personnel and office staff. On March 27, 2018, the Company amended the Higman Pension Plan to close it to all new entrants and cease all benefit accruals for periods after May 15, 2018 for all participants. The Company made contributions to the Higman Pension Plan of $8.2 million, $0.9 million and $0.5 million for the years ended December 31, 2023, 2022 and 2021, respectively.

The aggregate fair value of plan assets of the Company’s pension plans was $375.9 million and $341.1 million at December 31, 2023 and 2022, respectively. Pension assets were allocated among asset categories as follows:

	December 31,						Current Minimum, Target and Maximum
Asset Category	2023			2022			Allocation Policy
U.S. equity securities		51	%		50	%		45	%	— 50%	— 55%
International equity securities		20			20			12	%	— 20%	— 28%
Debt securities		29			30			20	%	— 30%	— 40%
Cash and cash equivalents		—			—			0	%	— 0%	— 0%
		100	%		100	%

At December 31, 2022, $4.8 million was held in cash as well as debt and equity securities classified within Level 1 of the valuation hierarchy. There were no investments within Level 3 of the valuation hierarchy at December 31, 2023 and 2022. All other plan assets are invested in common collective trusts and valued using the net asset value per share practical expedient and therefore not valued within the valuation hierarchy.

The Company’s investment strategy focuses on total return on invested assets (capital appreciation plus dividend and interest income). The primary objective in the investment management of assets is to achieve long-term growth of principal while avoiding excessive risk. Risk is managed through diversification of investments within and among asset classes, as well as by investing in asset classes offering sufficient liquidity and trading history.

The Company makes various assumptions when determining defined benefit plan costs including, but not limited to, the current discount rate and the expected long-term return on plan assets. Discount rates are determined annually and are based on a yield curve that consists of a hypothetical portfolio of high quality corporate bonds with maturities matching the projected benefit cash flows. The Company assumed that plan assets would generate a long-term rate of return of 6.75% in both 2023 and 2022. The Company developed its expected long-term rate of return assumption by evaluating input from investment consultants comparing historical returns for various asset classes with its actual and targeted plan investments. The Company believes that its long-term asset allocation, on average, will approximate the targeted allocation.

The Company’s pension plan funding strategy is to make annual contributions in amounts equal to or greater than amounts necessary to meet minimum government funding requirements. The plan’s benefit obligations are based on a variety of demographic and economic assumptions, and the pension plan assets’ returns are subject to various risks, including market and interest rate risk, making an accurate prediction of the pension plan contribution difficult. The Company’s pension plan funding was 115% of the pension plans’ accumulated benefit obligation at December 31, 2023, including both the Kirby Pension Plan and the Higman Pension Plan.

The Company sponsors an unfunded defined benefit health care plan that provides limited postretirement medical benefits to employees who met minimum age and service requirements, and to eligible dependents. The plan limits cost increases in the Company’s contribution to 4% per year. The plan is contributory, with retiree contributions adjusted annually. The plan eliminated coverage for future retirees as of December 31, 2011. The Company also has an unfunded defined benefit supplemental executive retirement plan (“SERP”) that was assumed in an acquisition in 1999. That plan ceased to accrue additional benefits effective January 1, 2000.

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The following table presents the change in benefit obligation and plan assets for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits												Other Postretirement Benefits
	Pension Plans						SERP						Postretirement Welfare Plan
	2023			2022			2023			2022			2023			2022
Change in benefit obligation
Benefit obligation at beginning of year	$	339,509		$	495,272		$	833		$	1,033		$	432		$	582
Service cost		3,695			6,538			—			—			—			—
Interest cost		18,356			14,779			43			29			22			17
Actuarial (gain) loss		13,241			(158,816	)		91			(74	)		65			(58	)
Gross benefits paid		(32,052	)		(12,665	)		(153	)		(155	)		(104	)		(109	)
Settlements		—			(5,599	)		—			—			—			—
Benefit obligation at end of year	$	342,749		$	339,509		$	814		$	833		$	415		$	432
Accumulated benefit obligation at end of year	$	326,987		$	325,274		$	814		$	833		$	415		$	432
Weighted-average assumption used to determine benefit obligation at end of year
Discount rate (a)	5.1%/5.2%				5.5	%		5.1	%		5.5	%		5.1	%		5.5	%
Rate of compensation increase	Service-based table			Service-based table				—			—			—			—
Health care cost trend rate
Initial rate		—			—			—			—			6.25	%		6.50	%
Ultimate rate		—			—			—			—			5.0	%		5.0	%
Years to ultimate		—			—			—			—		2029			2029
Change in plan assets
Fair value of plan assets at beginning of year	$	341,061		$	430,821		$	—		$	—		$	—		$	—
Actual return on plan assets		58,734			(72,402	)		—			—			—			—
Employer contribution		8,174			906			153			155			104			109
Gross benefits paid		(32,052	)		(12,665	)		(153	)		(155	)		(104	)		(109	)
Settlements		—			(5,599	)		—			—			—			—
Fair value of plan assets at end of year	$	375,917		$	341,061		$	—		$	—		$	—		$	—

(a)The 2023 discount rate was 5.1% for the Kirby Pension Plan and 5.2% for the Higman Pension Plan. The 2022 discount rate was 5.5% for both the Kirby Pension Plan and the Higman Pension Plan.

During the year ending December 31, 2023, actual returns on plan assets performed better than expected which improved the funding position.

During the year ending December 31, 2022, actual returns on plan assets performed less than expected which deteriorated the funding position but the overall funded position at December 31, 2022 was improved due to a decrease in the benefit obligation primarily due to an increase in the discount rate.

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The following table presents the funded status and amounts recognized in the Company’s consolidated balance sheet for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits												Other Postretirement Benefits
	Pension Plans						SERP						Postretirement Welfare Plan
	2023			2022			2023			2022			2023			2022
Funded status at end of year
Fair value of plan assets	$	375,917		$	341,061		$	—		$	—		$	—		$	—
Benefit obligations		(342,749	)		(339,509	)		(814	)		(833	)		(415	)		(432	)
Funded status and amount recognized at end of year	$	33,168		$	1,552		$	(814	)	$	(833	)	$	(415	)	$	(432	)
Amounts recognized in the consolidated balance sheets
Noncurrent asset		42,698			18,695			—			—			—			—
Current liability		—			—			(106	)		(106	)		(46	)		(49	)
Long-term liability		(9,530	)		(17,143	)		(708	)		(727	)		(369	)		(383	)
Amounts recognized in accumulated other comprehensive income
Net actuarial (gain) loss	$	(48,033	)	$	(25,449	)	$	391		$	324		$	(1,890	)	$	(2,299	)
Prior service cost (credit)		—			—			—			—			—			—
Accumulated other compensation income	$	(48,033	)	$	(25,449	)	$	391		$	324		$	(1,890	)	$	(2,299	)

The following table presents the expected cash flows for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits								Other Postretirement Benefits
	Pension Plans				SERP				Postretirement Welfare Plan
	2023		2022		2023		2022		2023		2022
Expected employer contributions
First year	$	1,770	$	8,374	$	—	$	—	$	—	$	—
Expected benefit payments (gross)
Year one	$	16,696	$	16,312	$	108	$	108	$	47	$	50
Year two		17,513		16,899		103		104		46		49
Year three		18,169		17,808		98		99		44		47
Year four		19,096		18,650		93		94		43		45
Year five		19,860		19,707		88		90		41		43
Next five years		108,717		110,417		337		359		167		176

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The components of net periodic benefit cost and other changes in plan assets and benefit obligations recognized in other comprehensive income for the Company’s defined benefit plans were as follows (in thousands):

	Pension Benefits
	Pension Plans									SERP
	2023			2022			2021			2023			2022			2021
Components of net periodic benefit cost
Service cost	$	3,695		$	6,538		$	7,961		$	—		$	—		$	—
Interest cost		18,356			14,779			14,239			43			29			31
Expected return on plan assets		(22,910	)		(28,399	)		(26,244	)		—			—			—
Amortization of actuarial loss		—			34			4,193			23			30			40
Net periodic benefit cost		(859	)		(7,048	)		149			66			59			71
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Current year actuarial (gain) loss		(22,583	)		(58,015	)		(44,583	)		91			(74	)		(12	)
Recognition of actuarial loss		—			(34	)		(4,193	)		(23	)		(30	)		(40	)
Total recognized in other comprehensive income		(22,583	)		(58,049	)		(48,776	)		68			(104	)		(52	)
Total recognized in net periodic benefit cost and other comprehensive income	$	(23,442	)	$	(65,097	)	$	(48,627	)	$	134		$	(45	)	$	19
Weighted average assumptions used to determine net periodic benefit cost
Discount rate (a)		5.5	%	3.0% / 3.1%			2.8% / 2.9%				5.5	%		3.0	%		2.8	%
Expected long-term rate of return on plan assets		6.75	%		6.75	%		6.75	%		—			—			—
Rate of compensation increase	Service-based table			Service-based table			Service-based table				—			—			—

(a)The 2023 discount rate for benefit cost is 5.5% for both the Kirby Pension Plan and the Higman Pension Plan. The 2022 discount rate for benefit cost is 3.0% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan.

The components of net periodic benefit cost and other changes in benefit obligations recognized in other comprehensive income for the Company’s postretirement benefit plan were as follows (in thousands):

	Other Postretirement Benefits
	Postretirement Welfare Plan
	2023			2022			2021
Components of net periodic benefit cost
Interest cost	$	22		$	17		$	17
Amortization of actuarial gain		(344	)		(394	)		(451	)
Net periodic benefit cost		(322	)		(377	)		(434	)
Other changes in benefit obligations recognized in other comprehensive income
Current year actuarial loss (gain)		65			(58	)		104
Recognition of actuarial gain		344			394			451
Total recognized in other comprehensive income		409			336			555
Total recognized in net periodic benefit cost and other    comprehensive income	$	87		$	(41	)	$	121
Weighted average assumptions used to determine net periodic benefit cost
Discount rate		5.5	%		3.0	%		2.8	%
Health care cost trend rate:
Initial rate		6.50	%		6.25	%		6.50	%
Ultimate rate		5.0	%		5.0	%		5.0	%
Years to ultimate	2029			2027			2025

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The Company also contributes to a multiemployer pension plan pursuant to a collective bargaining agreement which covers certain vessel crew members of its coastal operations and expires on April 30, 2025. The Company began participation in the Seafarers Pension Trust (“SPT”) with the Penn Maritime, Inc. acquisition on December 14, 2012.

Contributions to the SPT are made currently based on a per day worked basis and charged to expense as incurred and included in costs of sales and operating expenses in the consolidated statement of earnings. During 2023 and 2022, the Company made contributions of $0.4 million and $0.5 million, respectively, to the SPT. The Company’s contributions to the SPT did not exceed 5% of total contributions to the SPT in 2022. Total contributions for 2023 are not yet available. The Company did not pay any material surcharges in 2023 and 2022.

The federal identification number of the SPT is 13-6100329 and the Certified Zone Status is Green at December 31, 2022. The Company’s future minimum contribution requirements under the SPT are unavailable because actuarial reports for the 2023 plan year are not yet complete and such contributions are subject to negotiations between the employers and the unions. The SPT was not in endangered or critical status for the 2022 plan year, the latest period for which a report is available, as the funded status was in excess of 100%. Based on the most recent communication from the SPT, there would be no withdrawal liability if the Company chose to withdraw from the SPT although the Company currently has no intention of terminating its participation in the SPT.

The Company also contributes to a multiemployer pension plan pursuant to a collective bargaining agreement which covers certain employees of KDS in New Jersey and expires on October 8, 2028. The Company began participation in the Central Pension Fund of the International Union of Operating Engineers and Participating Employers (“CPF”) with the Stewart & Stevenson LLC acquisition on September 13, 2017.

Contributions to the CPF are made currently based on a fixed hourly rate for each hour worked or paid basis (in some cases contributions are made as a percentage of gross pay) and charged to expense as incurred and included in costs of sales and operating expenses in the consolidated statement of earnings. During 2023 and 2022, the Company made contributions of $0.6 and $0.7 million, respectively, to the CPF. Total contributions for the 2023 plan year are not yet available. The Company did not pay any material surcharges in 2023 and 2022.

The federal identification number of the CPF is 36-6052390 and the Certified Zone Status is Green at January 31, 2024. The Company’s future minimum contribution requirements under the CPF are unavailable because actuarial reports for the 2023 plan year, which ended January 31, 2024, are not yet complete and such contributions are subject to negotiations between the employers and the unions. The CPF was not in endangered or critical status for the 2022 plan year, ending January 31, 2023, the latest period for which a report is available, as the funded status was 107%. There would be no withdrawal liability if the Company chose to withdraw from the CPF although the Company currently has no intention of terminating its participation in the CPF.

In addition to the defined benefit plans, the Company sponsors various defined contribution plans for substantially all employees. The aggregate contributions to the plans were $26.9 million, $27.9 million, and $25.9 million in 2023, 2022, and 2021, respectively.

(13) Other Comprehensive Income (Loss)

The Company’s changes in other comprehensive income (loss) were as follows (in thousands):

	Year Ended December 31,
	2023									2022									2021
	Gross Amount			Income Tax (Provision) Benefit			Net Amount			Gross Amount			Income Tax (Provision) Benefit			Net Amount			Gross Amount			Income Tax Provision			Net Amount
Pension and postretirement benefits (a):
Amortization of net actuarial (gain) loss	$	(321	)	$	78		$	(243	)	$	(330	)	$	81		$	(249	)	$	3,782		$	(952	)	$	2,830
Actuarial gain		22,438			(5,467	)		16,971			58,147			(14,030	)		44,117			44,491			(10,774	)		33,717
Foreign currency translation adjustments		1,425			—			1,425			(1,049	)		—			(1,049	)		(1,061	)		—			(1,061	)
Total	$	23,542		$	(5,389	)	$	18,153		$	56,768		$	(13,949	)	$	42,819		$	47,212		$	(11,726	)	$	35,486

(a)Actuarial gains (losses) are amortized into other income (expense). (See Note 12 – Retirement Plans)

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(14) Contingencies and Commitments

In 2009, the Company was named by the Environmental Protection Agency (the “EPA”) as a Potentially Responsible Party (“PRP”) in addition to a group of approximately 250 named PRPs under the Comprehensive Environmental Response, Compensation and Liability Act of 1981 (“CERCLA”) with respect to a Superfund site, the Portland Harbor Superfund site (“Portland Harbor”) in Portland, Oregon. The site was declared a Superfund site in December 2000 as a result of historical heavily industrialized use due to manufacturing, shipbuilding, petroleum storage and distribution, metals salvaging, and electrical power generation activities which led to contamination of Portland Harbor, an urban and industrial reach of the lower Willamette River located immediately downstream of downtown Portland. The Company’s involvement arises from four spills at the site after it was declared a Superfund site, as a result of predecessor entities’ actions in the area. To date, there is no information suggesting the extent of the costs or damages to be claimed from the 250 notified PRPs. Based on the nature of the involvement at the Portland Harbor site, the Company believes its potential contribution is de minimis; however, to date neither the EPA nor the named PRPs have performed an allocation of potential liability in connection with the site nor have they provided costs and expenses in connection with the site.

On February 20, 2015, the Company was served as a defendant in a Complaint originally filed on August 14, 2014, in the U.S. District Court of the Southern District of Texas - Houston Division, USOR Site PRP Group vs. A&M Contractors, USES, Inc. et al. This is a civil action pursuant to the provisions of CERCLA and the Texas Solid Waste Disposal Act for recovery of past and future response costs incurred and to be incurred by the USOR Site PRP Group for response activities at the U.S. Oil Recovery Superfund Site. The property was a former sewage treatment plant owned by defendant City of Pasadena, Texas from approximately 1945 until it was acquired by U.S. Oil Recovery in January 2009. Throughout its operating life, the U.S. Oil Recovery facility portion of the USOR Site received and performed wastewater pretreatment of municipal and Industrial Class I and Class II wastewater, characteristically hazardous waste, used oil and oily sludges, and municipal solid waste. Associated operations were conducted at the MCC Recycling facility portion of the USOR Site after it was acquired by U.S. Oil Recovery from the City of Pasadena in January 2009. The EPA and the PRP Group entered into an Administrative Settlement Agreement and Order for Remedial Investigation Study (“Study”) in May 2015. The Study has not been completed by EPA to date. The Company joined as a member of the PRP Group companies at its pro-rata allocated share.

On October 13, 2016, the Company, as a successor to Hollywood Marine, Inc. (“Hollywood Marine”), was issued a General Notice under CERCLA by the EPA in which it was named as a PRP for liabilities associated with the SBA Shipyard Site located near Jennings, Louisiana (the “Site”). The Site was added to the EPA’s National Priorities List of sites under CERCLA in September 2016. SBA used the facility for construction, repair, retrofitting, sandblasting, and cleaning and painting of barges beginning in 1965. Three barge slips and a dry dock are located off the Mermentau River. The slips were used to dock barges during cleaning or repair. In 2001, a group of PRPs that had been former customers of the SBA Shipyard facility formed an organization called the SSIC Remediation, LLC (hereinafter, “the PRP Group Companies”) to address removal actions at the Site. In 2002, EPA approved an Interim Measures/Removal Action of Hazardous/Principal Threat Wastes at SBA Shipyards, Inc. (pursuant to RCRA Section 3008(h)) that was proposed by SBA Shipyard and the PRP Group Companies. Interim removal activities were conducted from March 2001 through January 2005 under an EPA 2002 Order and Agreement. In September 2012, the Louisiana Department of Environmental Quality requested EPA address the Site under CERCLA authority. The Company, as a successor to Hollywood Marine, joined the PRP Group Companies. The PRP Group Companies have submitted a draft Study work plan to EPA for their review and comment. Higman was named as a PRP in connection with its activities at the Site. Higman is not a participant in the PRP Group Companies.

With respect to the above sites, the Company has accrued a liability, if applicable, for its estimated potential liability for its portion of the EPA’s past costs claim based on information developed to date including various factors such as the Company’s liability in proportion to other PRPs and the extent to which such costs are recoverable from third parties.

On October 13, 2016, the tug Nathan E. Stewart and barge DBL 55, an ATB owned and operated by Kirby Offshore Marine, LLC, a wholly owned subsidiary of the Company, ran aground at the entrance to Seaforth Channel on Atholone Island, British Columbia. The grounding resulted in a breach of a portion of the Nathan E. Stewart’s fuel tanks causing a discharge of diesel fuel into the water. The USCG and the NTSB designated the Company as a party of interest in their investigation as to the cause of the incident. The Canadian authorities including Transport Canada and the Canadian Transportation Safety Board investigated the cause of the incident. On October 10, 2018, the Heiltsuk First Nation filed a civil action in the British Columbia Supreme Court against a subsidiary of the Company, the master and pilot of the tug, the vessels and the Canadian government seeking unquantified damages as a result of the incident. On May 1, 2019, the Company filed a limitation action in the Federal Court of Canada seeking limitation of liability relating to the incident as provided under admiralty law. The Heiltsuk First Nation’s civil claim has been consolidated into the Federal Court limitation action as of July 26, 2019 and it is expected that the Federal Court of Canada will decide all claims against the Company. The Company is unable to estimate the potential exposure in the civil proceeding. The Company has various insurance policies covering liabilities including pollution, property, marine and general liability and believes that it has satisfactory insurance coverage for the cost of cleanup and salvage operations as well as other potential liabilities arising from the incident. The Company believes its accrual of such estimated liability is adequate for the incident and does not expect the incident to have a material adverse effect on its business or financial condition.

76

In addition, the Company is involved in various legal and other proceedings which are incidental to the conduct of its business, none of which in the opinion of management will have a material effect on the Company’s financial condition, results of operations or cash flows. Management believes its accrual of such estimated liability is adequate and believes that it has adequate insurance coverage or has meritorious defenses for these other claims and contingencies.

Certain Significant Risks and Uncertainties. The preparation of financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. However, in the opinion of management, the amounts would be immaterial.

The Company has issued guaranties or obtained standby letters of credit and performance bonds supporting performance by the Company and its subsidiaries of contractual or contingent legal obligations of the Company and its subsidiaries incurred in the ordinary course of business. The aggregate notional value of these instruments is $26.7 million at December 31, 2023, including $12.1 million in letters of credit and $14.6 million in performance bonds. All of these instruments have an expiration date within two years. The Company does not believe demand for payment under these instruments is likely and expects no material cash outlays to occur in connection with these instruments.

(15) Related Party Transactions

David W. Grzebinski, President and Chief Executive Officer of the Company, is a member of the board of directors for ABS, a not-for-profit that provides global classification services to the marine, offshore and gas industries. The Company paid ABS $1.5 million in 2023, $1.3 million in 2022, and $1.6 million in 2021 to perform audits and surveys of the Company’s vessels in the ordinary course of business.

Mr. Grzebinski is a member of the board of directors of UK Protection & Indemnity Association (“UK P&I”), a mutual marine protection and indemnity organization that provides protection and indemnity insurance for third party liabilities and expenses arising from vessel operations. The Company’s marine fleet is insured on a pro rata share basis through UK P&I and Standard Mutual. The Company paid $3.6 million during 2023 in premiums for coverage in the 2023-2024 policy period, $3.4 million during 2022 in premiums for coverage in the 2022-2023 policy period, and $3.2 million in 2021 in premiums for coverage in the 2021-2022 policy period in the ordinary course of business.

Amy D. Husted, Vice President, General Counsel and Secretary of the Company, is a member of the board of directors of Signal Mutual Indemnity Association Ltd (“Signal”), a group self-insurance not-for-profit organization authorized by the U.S. Department of Labor as a longshore worker’s compensation insurance provider. The Company has been a member of Signal since it was established in 1986. The Company paid Signal $0.7 million in 2023, $0.5 million in 2022 and $0.6 million in 2021 in the ordinary course of business.

The husband of Ms. Husted is a partner in the law firm of Clark Hill PLC. The Company paid the law firm $0.9 million in 2023, $1.0 million in 2022, and $2.9 million in 2021 for legal services in connection with matters in the ordinary course of business.

The brother of Christian G. O’Neil, President of Kirby Inland Marine, LP, Kirby Offshore Marine, LLC, San Jac Marine, LLC and Kirby Offshore Wind, LLC, is a partner in the law firm of W. Sean O’Neil Attorney at Law. The Company paid the law firm $0.1 million in 2023, $0.1 million in 2022, and $0.1 million in 2021 for legal services in the ordinary course of business.

Rocky B. Dewbre, a director of the Company, serves as President and Chief Operating Officer of Mansfield Service Partners. Mansfield Service Partners is under the same common control as O’Rourke Marine Services (“O’Rourke”), a distributor of lubricants, fuels, and environmental services. The Company paid O’Rourke $29.4 million in 2023 in the ordinary course of business.

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PART IV

Item 15. Exhibits and Financial Statement Schedules

1. Financial Statements

Included in Part III of this report on pages 49 to 77:

Report of Independent Registered Public Accounting Firm (KPMG LLP, Houston, TX, PCAOB ID 185).

Report of Independent Registered Public Accounting Firm.

Consolidated Balance Sheets, December 31, 2023 and 2022.

Consolidated Statements of Earnings, for the years ended December 31, 2023, 2022, and 2021.

Consolidated Statements of Comprehensive Income, for the years ended December 31, 2023, 2022, and 2021.

Consolidated Statements of Cash Flows, for the years ended December 31, 2023, 2022, and 2021.

Consolidated Statements of Stockholders’ Equity, for the years ended December 31, 2023, 2022, and 2021.

Notes to Consolidated Financial Statements, for the years ended December 31, 2023, 2022, and 2021.

2. Financial Statement Schedules

All schedules are omitted as the required information is inapplicable or the information is presented in the consolidated financial statements or related notes.

3. Exhibits

EXHIBIT INDEX

Exhibit
Number		Description of Exhibit
3.1	—	Restated Articles of Incorporation of the Company with all amendments to date (incorporated by reference to Exhibit 3.1 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2014).
3.2	—	Bylaws of the Company with all amendments to date (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on October 28, 2022).
4.1	—	See Exhibits 3.1 and 3.2 hereof for provisions of our Restated Articles of Incorporation of the Company with all amendments to date and the Bylaws of the Company with all amendments to date (incorporated, respectively, by reference to Exhibit 3.1 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2014 and Exhibit 3.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on October 28, 2022).
4.2	—	Long-term debt instruments are omitted pursuant to Item 601(b)(4) of Regulation S-K. The Registrant will furnish copies of such instruments to the Commission upon request.
10.1	—	Note Purchase Agreement dated February 3, 2022 (incorporated by reference to Exhibit 10.1 to the Registrant’s Form 8-K filed with the Commission on February 8, 2022).
10.2	—	Credit Agreement dated July 29, 2022 among Kirby Corporation, JPMorgan Chase Bank, N.A., as Administrative Agent, and the banks named therein (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on July 29, 2022).
10.3†	—	Incentive and Retention Award Agreement of David W. Grzebinski dated February 25, 2021 (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on February 26, 2021).
10.4†	—	Incentive and Retention Award Agreement of Christian G. O’Neil dated February 25, 2021 (incorporated by reference to Exhibit 10.2 to the Registrant’s Current Report on Form 8-K filed with the Commission on February 26, 2021).
10.5†	—	Annual Incentive Plan Guidelines for 2023 (incorporated by reference to Exhibit 10.6 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2022).
10.6†	—	Amended and Restated Annual Incentive Plan 2023 Plan Year Guidelines (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on March 24, 2023).
10.7†*	—	Annual Incentive Plan Guidelines for 2024.
10.8†	—	2005 Stock and Incentive Plan (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on April 29, 2021).

78

Exhibit
Number		Description of Exhibit
10.9†	—	2000 Nonemployee Director Stock Plan (incorporated by reference to Exhibit 10.2 to the Registrant’s Current Report on Form 8-K filed with the Commission on April 29, 2021).
10.10†	—	Nonemployee Director Compensation Program effective April 24, 2018 (incorporated by reference to Exhibit 10.2 to the Registrant’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2018).
10.11†*		Nonemployee Director Compensation Program effective January 29, 2024
10.12†	—	Deferred Compensation Plan for Key Employees (As Amended and Restated Effective April 1, 2022 and incorporated by reference to Exhibit 10.3 to the Registrant’s Quarterly Report on Form 10-Q filed with the Commission on May 9, 2022).
10.13†	—	Change of Control Agreement by and between Kirby Corporation and David W. Grzebinski dated May 16, 2022 (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on May 20, 2022).
10.14†	—	Change of Control Agreement by and between Kirby Corporation and Raj Kumar dated May 16, 2022 (incorporated by reference to Exhibit 10.2 to the Registrant’s Current Report on Form 8-K filed with the Commission on May 20, 2022).
10.15†	—	Change of Control Agreement by and between Kirby Corporation and Christian G. O’Neil dated May 16, 2022 (incorporated by reference to Exhibit 10.3 to the Registrant’s Current Report on Form 8-K filed with the Commission on May 20, 2022).
10.16†	—	Change of Control Agreement by and between Kirby Corporation and Amy D. Husted dated May 16, 2022 (incorporated by reference to Exhibit 10.4 to the Registrant’s Current Report on Form 8-K filed with the Commission on May 20, 2022).
10.17†		Amendment to Change of Control Agreement by and between Kirby Corporation and David W. Grzebinski dated March 6, 2023 (incorporated by reference to Exhibit 10.4 to the Registrant’s Quarterly Report on Form 10-Q filed with the Commission on May 8, 2023).
10.18†		Amendment to Change of Control Agreement by and between Kirby Corporation and Raj Kumar dated March 6, 2023 (incorporated by reference to Exhibit 10.5 to the Registrant’s Quarterly Report on Form 10-Q filed with the Commission on May 8, 2023).
10.19†		Amendment to Change of Control Agreement by and between Kirby Corporation and Christian G. O’Neil dated March 6, 2023 (incorporated by reference to Exhibit 10.6 to the Registrant’s Quarterly Report on Form 10-Q filed with the Commission on May 8, 2023).
10.20	—	Cooperation Agreement dated February 3, 2023 by and among the Company and JCP Investment Management, LLC and certain of its affiliates and associates (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed with the Commission on February 3, 2023).
21.1*	—	Consolidated Subsidiaries of the Registrant.
23.1*	—	Consent of Independent Registered Public Accounting Firm.
31.1*	—	Certification of Chief Executive Officer Pursuant to Rule 13a-14(a).
31.2*	—	Certification of Chief Financial Officer Pursuant to Rule 13a-14(a).
32*	—	Certification Pursuant to 18 U.S.C. Section 1350 (As adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002).
97*	—	Kirby Corporation Clawback Policy
101.INS*	—	Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document
101.SCH*	—	Inline XBRL Taxonomy Extension Schema with Embedded Linkbase documents
104*	—	Cover Page Interactive Data File (embedded within the Inline XBRL document)

* Filed herewith.

† Management contract, compensatory plan or arrangement.

Item 16. Form 10-K Summary

Not applicable

79

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	KIRBY CORPORATION
	(REGISTRANT)
	By:	/s/ RAJ KUMAR
		Raj Kumar
		Executive Vice President and
		Chief Financial Officer
Dated: February 20, 2024

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

Signature	Capacity	Date
/s/ JOSEPH H. PYNE	Chairman of the Board and Director	February 20, 2024
Joseph H. Pyne
/s/ DAVID W. GRZEBINSKI	President, Chief Executive Officer,	February 20, 2024
David W. Grzebinski	and Director
	(Principal Executive Officer)
/s/ RAJ KUMAR	Executive Vice President and	February 20, 2024
Raj Kumar	Chief Financial Officer
	(Principal Financial Officer)
/s/ RONALD A. DRAGG	Vice President, Controller and	February 20, 2024
Ronald A. Dragg	Assistant Secretary
	(Principal Accounting Officer)
/s/ ANNE-MARIE N. AINSWORTH	Director	February 20, 2024
Anne-Marie N. Ainsworth
/s/ RICHARD J. ALARIO	Director	February 20, 2024
Richard J. Alario
/s/ TANYA S. BEDER	Director	February 20, 2024
Tanya S. Beder
/s/ BARRY E. DAVIS	Director	February 20, 2024
Barry E. Davis
/s/ ROCKY B. DEWBRE	Director	February 20, 2024
Rocky B. Dewbre
/s/ SUSAN W. DIO	Director	February 20, 2024
Susan W. Dio
/s/ RICHARD R. STEWART	Director	February 20, 2024
Richard R. Stewart
/s/ WILLIAM M. WATERMAN	Director	February 20, 2024
William M. Waterman
/s/ SHAWN D. WILLIAMS	Director	February 20, 2024
Shawn D. Williams

80

EX-10.7

EXHIBIT 10.7

ANNUAL INCENTIVE PLAN

2024 Plan Year

Guidelines

KIRBY CORPORATION

EFFECTIVE: January 2024

TABLE OF CONTENTS

Introduction	2
The 2024 Annual Incentive Plan	3
Plan Objectives	3
Business Groups	3
Performance Period	3
Eligibility	4
Individual Bonus Targets	4
Aggregate Payment Amount	4
Performance Measures	4
Business Group Weighting	5
Performance Standards for Interim Incentive Payment Calculations	6
Administration	8

1

Introduction

Kirby Corporation (together with its subsidiaries, “Kirby” or the “Company”) established the 2024 Annual Incentive Plan (the “Plan”) to focus employees of the Company on identifying and achieving business strategies that lead to increased stockholder value. The Plan is also intended to reward superior performance by employees and their contribution to achieving Kirby’s objectives.

Certain aspects of this Plan are complex. Although these Guidelines establish rules for Plan operation, those rules may not work in all circumstances. Therefore, the Compensation Committee of the Kirby Board of Directors has discretion to interpret these Guidelines to assure the awards are consistent with the Plan’s purposes and the Company’s interests. All decisions by the Compensation Committee shall be final and binding.

Unless resolutions of the Compensation Committee expressly provide otherwise, awards granted under the Plan shall constitute performance awards granted under Article V of the Kirby Corporation 2005 Stock and Incentive Plan and are subject to the terms and provisions of such Plan that apply to performance awards.

The Plan may be amended, modified or terminated at any time without prior notice by written authorization of the Compensation Committee or the Board of Directors of Kirby Corporation.

2

The 2024 Annual Incentive Plan

Each award granted under the Plan is an award for Company performance or a combination of Company and Business Group performance. Awards are generally based on achieving the Company Performance Goal as well as additional Company, Business Group and individual performance measures and objectives. Once the Company Performance Goal is reached, participants in the Plan become eligible for an incentive bonus payment.

All amounts paid to participants pursuant to the Plan shall be subject to any policy relating to the recovery of erroneously awarded incentive compensation that may hereafter be adopted by the Company to comply with Securities and Exchange Commission rules or New York Stock Exchange listing standards.

Plan Objectives

The key objectives of the Plan are:

•Provide an annual incentive plan that drives performance toward objectives critical to creating stockholder value.

•Offer competitive cash compensation opportunities to key Kirby employees.

•Reward outstanding achievement by employees who directly affect Kirby’s results.

•Assist Kirby in attracting and retaining high quality employees.

•Reflect both quantitative and qualitative performance factors in actual bonus payouts.

•Ensure that incentive payments made by the Company are fully deductible by the Company.

Business Groups

The following Business Groups are designated for purposes of the Plan:

Kirby Corporate Services (“KCS”)	ThermoKing (“TK/CON”)
Kirby Inland Marine, LP (“KIM”)1	Kirby Engine Systems, Inc. (“KES”)
Kirby Offshore Marine, LLC (“KOM”)	Atlantic and Florida Detroit Diesel Allison (“DDAs”)
S&S and United (S&S UE)	KDS Consolidated (KDS)

1 KIM includes Kirby Ocean Transport Company, San Jac Marine and Osprey Line, LLC.

Performance Period

Performance is measured on a calendar year basis for the Plan. The Performance Period begins on January 1, 2024 and ends on December 31, 2024. Except as expressly provided in these Guidelines in the case of new employees or termination of employment, incentive compensation payments under the Plan are for the full year 2024 and shall not be reduced for the period between the commencement of the Performance Period and the date on which the Compensation Committee approves these Guidelines and the individual bonus targets for participants in the Plan.

3

Eligibility

•Generally, managerial employees and KIM wheelhouse employees classified as Captain, Relief Captain or Pilot, are eligible for participation. Selection for participation in the Plan is based upon each position’s ability to impact long-term financial results of the Company and designation by management.

•To be eligible to receive an incentive payment under the Plan, participants must be employed on the last day of the Performance Period and on the date bonuses are paid for the Performance Period, unless their termination reason is death or disability or if they meet the requirements of a retirement. For the purposes of the Plan, the definition of retirement is a calculation resulting in either 65 years of age on termination date or age plus service is greater than or equal to 80.

•Participation in the Plan in 2024 does not guarantee participation in similar plans in future years. Participants in the Plan or in similar plans in future years will be notified annually of their selection for participation.

Individual Bonus Targets

Each participant will be assigned a target bonus level defined as a percentage of base salary earned during the Performance Period. This bonus target is based on competitive market practices, as well as the employee’s ability to impact long-term Company performance. Market practices will be determined using data from either general industry, the marine transportation industry or the diesel engine services industry, depending upon the individual position being considered.

Aggregate Payment Amount

At the end of the year, a preliminary incentive payment amount will first be calculated for each participant in the Plan to determine the Aggregate Payment Amount for all participants for the year. The preliminary incentive payment amount for each participant will be calculated as of December 31, 2024 based on the target incentive level for such participant and the calculation formulas described in these Guidelines. The Aggregate Payment Amount under the Plan shall equal the sum of all such preliminary incentive payment amounts.

The Company will be obligated to pay out the full Aggregate Payment Amount to eligible participants, subject to the discretion of the Compensation Committee, and the Chief Executive Officer to the extent authorized under these Guidelines, with respect to the allocation of the Aggregate Payment Amount among individual participants. Therefore, the Company’s obligation to pay out the Aggregate Payment Amount becomes fixed on the last day of the Performance Period.

The Compensation Committee, and the Chief Executive Officer if applicable, may determine the amount of the bonus paid to any participant based on the performance measures described in the Plan or any other criteria deemed appropriate in its discretion, provided that in no event will the aggregate incentive payments made pursuant to the Plan exceed the Aggregate Payment Amount.

Performance Measures

The performance measures for the Plan are:

•EBITDA (Earnings before interest, taxes, depreciation and amortization)

•EPS (Earnings per share)

•Return on Total Capital (Earnings before interest and taxes divided by average capital)

•OP/ESG (metrics set on annual basis)

4

Annual performance targets will be established for each measure based on Kirby’s budget for the year and each of the performance measures will have the following weight in calculating the preliminary incentive payment amount for each participant:

	Performance Measures for Incentive Payment Calculations
Division	Business Group	Measure 1	Measure 2	Measure 3	Measure 4
Corporate	Kirby Corporate Services (KCS)	EBITDA 40%	EPS 30%	ROTC 10%	OP/ESG 20%
Marine	Kirby Inland Marine (KIM)1	EBITDA 80%			OP/ESG 20%
Marine	Kirby Offshore Marine (KOM)	EBITDA 80%			OP/ESG 20%
Marine	Marine Shared (Marine)	EBITDA 80%			OP/ESG 20%
D&S	Kirby Engine Systems (KES)	EBITDA 80%			OP/ESG 20%
D&S	ThermoKing (TK/CON)2	EBITDA 80%			OP/ESG 20%
D&S	Detroit Diesel Allison (DDAs)	EBITDA 80%			OP/ESG 20%
D&S	United Engines (S&S MFG)	EBITDA 80%			OP/ESG 20%
D&S	S&S Rental (S&S MFG)	EBITDA 80%			OP/ESG 20%
D&S	S&S Distribution/Training (S&S MFG)	EBITDA 80%			OP/ESG 20%
D&S	S&S Manufacturing (S&S MFG)	EBITDA 80%			OP/ESG 20%
D&S	KDS Consolidated (KDS)	EBITDA 80%			OP/ESG 20%

(1) KIM includes Kirby Ocean Transport Company and Osprey Line, LLC. and San Jac. Marine, LP

(2) Thermo King includes Convoy

(3) EBITDA (Earnings before interest, taxes, depreciation and amortization)

(4) Earnings per share

(5) ROTC (Return on total capital)

Business Group Weighting

Calculation of the preliminary incentive payment amount for Business Group employees will be based primarily on Business Group performance with a defined portion based on Company performance. Calculation of the preliminary incentive payment amount for employees of KCS will be based on Company performance. Specific weightings are set forth in the following table:

Business Group	Corp	KIM	KOM	KDS	KES
KCS	100%
KIM	30%	70%
KOM	30%		70%
Marine President (Marine)	50%	35%	15%
Marine Shared (Marine)	30%	50%	20%
KES	30%				70%
KES President	50%				50%
United/S&S	30%			70%
DDAs	30%			70%
TK/CON	30%			70%
KDS President (KDS)	50%			50%
KDS Shared (KDS)	30%			70%

5

Performance Standards for Incentive Payment Calculations

Corporate and Kirby Inland Marine
Performance Level	Definition	Relationship to Budget	% of Target Used for Calculation
Below Threshold	Performance did not meet minimum level	less than 80% of budget	0%
Threshold	Minimum acceptable performance for payout	80% of budget	50%
Target	Expected performance at stretch level	100% of budget	100%
Maximum	Outstanding performance	120% of budget	200%

Kirby Offshore Marine
Performance Level	Definition	Relationship to Budget	% of Target Used for Calculation
Below Threshold	Performance did not meet minimum level	less than 60% of budget	0%
Threshold	Minimum acceptable performance for payout	60% of budget	50%
Target	Expected performance at stretch level	100% of budget	100%
Maximum	Outstanding performance	150%of budget	200%

S&S Distribution, Rental, United, Training Center, KDS MFG
Performance Level	Definition	Relationship to Budget	% of Target Used for Calculation
Below Threshold	Performance did not meet minimum level	less than 60% of budget	0%
Threshold	Minimum acceptable performance for payout	60% of budget	50%
Target	Expected performance at stretch level	100% of budget	100%
Maximum	Outstanding performance	140% of budget	200%

ThermoKing, Detroit Diesel Allison
Performance Level	Definition	Relationship to Budget	% of Target Used for Calculation
Below Threshold	Performance did not meet minimum level	less than 60% of budget	0%
Threshold	Minimum acceptable performance for payout	60% of budget	50%
Target	Expected performance at stretch level	100% of budget	100%
Maximum	Outstanding performance	150% of budget	200%

6

KDS President & Shared Employees
Performance Level	Definition	Relationship to Budget	% of Target Used for Calculation
Below Threshold	Performance did not meet minimum level	less than 70% of budget	0%
Threshold	Minimum acceptable performance for payout	70% of budget	50%
Target	Expected performance at stretch level	100% of budget	100%
Maximum	Outstanding performance	130% of budget	200%

KES – Kirby Engine Systems
Performance Level	Definition	Relationship to Budget	% of Target Used for Calculation
Below Threshold	Performance did not meet minimum level	less than 75% of budget	0%
Threshold	Minimum acceptable performance for payout	75% of budget	50%
Target	Expected performance at stretch level	100% of budget	100%
Maximum	Outstanding performance	135%of budget	200%

•Between the threshold and maximum percentages of budget achieved for each performance measure, there is a linear relationship between the percentage of budget achieved and the resulting percentage of the target payout percentage used in calculating payout amounts. As examples, 90% of budget for KIM would result in 75% of target used in the calculation of a preliminary payment amount and 105% of budget would result in 125% of target used for the calculation of a preliminary payment amount.

•The target amount determined for each performance measure is then multiplied by the weight for the performance measure and the results are added together to produce a total Company or Business Group payout percentage of the target incentive that is applied to each individual participant to calculate the Aggregate Payout Amount under the Plan.

•The Compensation Committee and the Chief Executive Officer shall in their discretion allocate the Aggregate Payment Amount among eligible participants; provided that only the Compensation Committee shall have the authority to allocate payment amounts to eligible participants (i) who are “officers” for purposes of Section 16 of the Securities Exchange Act of 1934, (ii) whose bonus target is 50% or more of base salary or (iii) whose base salary is $300,000 or more (collectively “Specified Participants”). In allocating the Aggregate Payment Amount, the Compensation Committee and the Chief Executive Officer may consider, but shall not be bound by, the preliminary incentive payment amount calculated for each participant.

•The Compensation Committee has discretion to modify the performance measures or adjust the calculation of the preliminary incentive payment amounts to adjust for acquisitions, divestures and other material business events.

•The aggregate amount of incentive payments made to participants in the Plan must equal the Aggregate Payment Amount.

•Notwithstanding the foregoing or any provision of the Plan to the contrary, no participant may receive an amount more than 200% of the individual bonus target established for such participant (the “Maximum Payment”).

7

Administration

Incentive Payments

A participant’s final incentive bonus payment is paid out in cash within 90 days following the end of the Company’s fiscal year, based on audited financial statements of the Company.

Eligibility Limitation

Participants must be employed by the Company on the last day of the Performance Period and on the date bonuses are paid in order to receive a bonus, unless otherwise provided for in the Plan.

Special Circumstances

The Compensation Committee will have the sole authority to resolve disputes related to Plan administration. Decisions made by the Compensation Committee will be final and binding on all participants. The Compensation Committee has the sole discretion to determine the bonuses for newly hired, terminated, transferred and promoted employees, but will generally award bonuses based on the following provisions.

New Employees

For employees hired after the beginning of a Performance Period who are selected for participation in the Plan, the preliminary incentive payment will be prorated for the portion of the Performance Period during which they were employees of the Company, subject to the Termination of Employment restrictions.

Termination of Employment

If a participant’s employment terminates prior to the last day of the Performance Period or prior to the date bonuses are paid for the Performance Period, for any reason other than death, retirement or disability, the participant will be ineligible to receive a bonus.

If a participant’s employment terminates before the end of the full Performance Period or before the date bonuses are paid for the Performance Period as a result of death, retirement or disability, the preliminary incentive payment for the participant (or the participant’s heirs) will be prorated at the end of the Performance Period based upon actual performance and base wages earned while employed during the Performance Period.

Transfer

The preliminary incentive payment for a participant who is transferred between Business Groups during the year will be a weighted bonus based upon the time spent at each of the Business Groups. In calculating a weighted bonus, relevant Company and Business Group performance measures will be calculated for the full Performance Period and then a blended bonus will be calculated based on the time spent at each Business Group.

Promotions

The preliminary incentive payment for a participant who is promoted or reassigned during any Performance Period and whose bonus target is subsequently increased or decreased will be a weighted bonus, based on the service before and after the promotion or reassignment.

8

Compensation Committee

The Plan shall be administered by the Compensation Committee. The Compensation Committee shall have the authority to interpret the provisions of the Plan and these Guidelines, to adopt such rules for carrying out the Plan as it may deem advisable, to decide conclusively all questions arising with respect to the Plan and to make all other determinations and take all other actions necessary or desirable for the administration of the Plan. All decisions and acts of the Compensation Committee shall be final and binding upon all affected parties.

In administering the Plan the Compensation Committee will:

•Approve the designation of Business Groups within the Company

•Approve the Company Performance Goal

•Approve other performance measures used and the Threshold, Target and Maximum budget performance levels for purposes of calculating preliminary incentive payment amounts and the Aggregate Payment Amount

•Approve linkage for participants to Company and Business Group performance

•Approve the individual bonus targets for all Specified Participants

•Approve the Aggregate Payment Amount to be paid to participants in the Plan

•Determine in its discretion the final incentive payments for participants.

The total amount of the incentive payments made to participants pursuant to the Plan must equal, and may not exceed, the Aggregate Payment Amount.

Chief Executive Officer (CEO)

The CEO has primary responsibility for recommending Plan Guidelines to the Committee and for delegating administrative duties associated with the Plan. The Compensation Committee may delegate additional administrative duties to the CEO or any Company officer. The CEO may make recommendations, subject to Compensation Committee approval, with respect to the incentive payment to any participant.

Chief Financial Officer (CFO)

The CFO is responsible for calculating performance under the Plan. The CFO will:

•Provide annual reports to the Compensation Committee and the CEO on each Business Group’s performance at the end of the fiscal year

•Maintain a financial information system that reports results on an estimated quarterly and annual basis

•Coordinate with the Company’s auditors to properly recognize any accounting expense associated with incentive payments under the Plan

•Provide the VP – of HR with the performance results of each Business Group as well as overall Company performance

Chief Human Resources Officer or functional equivalent (CHRO)

The CHRO has responsibility for administration of the Plan and will:

•Develop and recommend eligible participants and target bonus guidelines

•Coordinate communications with participants, including materials to facilitate understanding the Plan’s objectives and goals

9

•Calculate participants’ preliminary incentive payment amounts, using the performance factors provided by the CFO

•Process paperwork approving individual incentive payments

Business Group Presidents and Vice Presidents will:

•Recommend participants in the Plan

•Coordinate with the CFO to determine any significant changes in business conditions for purposes of reviewing the Threshold, Target and Maximum performance objectives

•Assure that participants are informed of the actual incentive payment to be made for the Performance Period

10

EX-10.11

EXHIBIT 10.11

KIRBY CORPORATION

Nonemployee Director Compensation Program

Annual Director Fee

1.Each director will receive an annual fee of $85,000, payable in four equal quarterly payments to be made at the end of each calendar quarter, unless the director elects to receive (a) a stock option for shares of Kirby common stock or (b) restricted shares of Kirby common stock, in lieu of all or part of the cash fee. The fee will be prorated for any director elected between annual stockholder meetings.

2.The election to receive a stock option or restricted stock in lieu of director fees will be made annually. Except as provided in the next sentence, any director who elects to receive a stock option or restricted stock in lieu of all or part of the annual fee for the year following any annual meeting of stockholders must give written notice of that election to Kirby no later than the December 31 preceding such annual meeting. A newly elected director must give written notice of his or her election to receive a stock option or restricted stock in lieu of all or part of the annual fee no later than 30 days after the date of his or her first election as a director.

3.The stock option shall be issued on the following terms:

(a)The number of shares of stock subject to the option will be equal to (i) the portion of the annual fee that a director elects to receive in the form of a stock option divided by (ii) the fair market value of a share of stock on the date of grant multiplied by (iii) 3, with the result then rounded to the nearest whole share.

(b)The exercise price per share will be the fair market value on the date of grant. The fair market value of a share of stock means the closing price on the New York Stock Exchange on the date of reference.

(c)The option will vest one-fourth on the first quarterly payment date, one-fourth on the second quarterly payment date, one-fourth on the third quarterly payment date and one-fourth on the fourth quarterly payment date or, in the case of a director elected between annual stockholder meetings, in equal parts on the remaining quarterly payment dates prior to the first anniversary of the most recent annual meeting of stockholders.

(d)The option will be subject to the terms of the plan under which it is issued, including without limitation provisions relating to vesting, exercise, termination and transferability.

4.The restricted stock shall be issued on the following terms:

DOCPROPERTY "xB" 45577060.7

(a)The number of shares of restricted stock will be equal to (i) the portion of the annual fee that a director elects to receive in the form of restricted stock divided by (ii) the fair market value of a share of stock on the date of grant multiplied by (iii) 1.2, with the result then rounded to the nearest whole share.

(b)The fair market value of a share of stock means the closing price on the New York Stock Exchange on the date of reference.

(c)The restricted stock will vest one-fourth on the first quarterly payment date, one-fourth on the second quarterly payment date, one-fourth on the third quarterly payment date and one-fourth on the fourth quarterly payment date or, in the case of a director elected between annual stockholder meetings, in equal parts on the remaining quarterly payment dates prior to the first anniversary of the most recent annual meeting of stockholders.

(d)The restricted stock will be subject to the terms of the plan under which it is issued, including without limitation provisions relating to vesting and transferability.

5.Except as provided in the next sentence, the date of grant of an option or restricted stock granted in lieu of the annual fee means the second business day after Kirby’s first quarter earnings conference call following the election by the director to receive the fee in the form of a stock option or restricted stock instead of cash. For a newly elected director, the date of grant means the date of his or her election to receive a stock option or restricted stock in lieu of cash fees.

6.The quarterly payment of cash fees and vesting of stock options and restricted stock are contingent on a director's continuing to serve in that capacity on each such quarterly payment or vesting date.

Annual Chairman of the Board, Committee Chairman and Presiding Director Fees

7.The Chairman of the Board will receive an annual fee of $150,000. The Chairman of the Audit Committee will receive an annual fee of $20,000. The Chairman of the Compensation Committee will receive an annual fee of $15,000. The Chairman of the Governance Committee will receive an annual fee of $10,000. The director selected to be the presiding director at executive sessions of non-management directors will receive an annual fee of $20,000. In addition, each director will receive an annual fee of $7,500 for each committee of the board on which he or she serves. All of such fees will be payable in four equal quarterly payments to be made at the end of each calendar quarter. The Chairman of the Board, committee chairman, presiding director and committee member fees will be prorated for any director who is elected to such position between annual meetings of the board of directors.

8.The quarterly payment of the Chairman of the Board, committee chairman, presiding director and committee member fees is contingent on a director’s continuing to serve in such position on each such quarterly payment date.

Automatic Restricted Stock Grants

DOCPROPERTY "xB" 45577060.7

9.Each director will receive $167,500 in value of restricted shares of Kirby common stock following each annual meeting of stockholders, except that a director elected between annual stockholder meetings will receive a prorated dollar value of restricted stock for the year in which he or she is first elected.

10.The restricted stock shall be issued on the following terms:

(a)The number of shares of restricted stock will be equal to (i) the dollar value divided by (ii) the fair market value of a share of stock on the date of grant multiplied by (iii) 1.2, with the result then rounded to the nearest whole share.

(b)The fair market value of a share of stock means the closing price on the New York Stock Exchange on the date of grant, which shall be the second business day after Kirby’s first quarter earnings conference call, except that for a director elected between annual stockholder meetings, the date of grant for the initial prorated grant shall be determined as follows:

(i)If the director is elected at a regular quarterly meeting of the Board of Directors, the date of grant shall be the second business day after Kirby’s earnings conference call for the immediately preceding quarter.

(ii)If the director is elected at any other time, the date of grant shall be the date of his or her election.

(c)The restricted stock will vest six months after the date of grant.

(d)The restricted stock will be subject to the terms of the plan under which it is issued, including without limitation provisions relating to vesting and transferability.

Discretionary Stock Option and Restricted Stock Grants

11.The Compensation Committee or the Board of Directors, as applicable, may, in its discretion, grant options and restricted stock to directors as permitted by and subject to the terms of the plan under which such grants are issued, including without limitation provisions relating to vesting, exercise, termination and transferability.

General

12.This compensation program may be amended, modified or terminated by the board at any time.

13.This compensation program applies only to directors of Kirby who are not employees of Kirby or any of its subsidiaries.

14.This compensation program is effective January 29, 2024 and amends and restates in its entirety the Nonemployee Director Compensation Program previously in effect.

DOCPROPERTY "xB" 45577060.7

EX-21.1

EXHIBIT 21.1

KIRBY CORPORATIONCONSOLIDATED SUBSIDIARIES OF THE REGISTRANTAT DECEMBER 31, 2023

	Domicile of Incorporation
KIRBY CORPORATION – PARENT AND REGISTRANT	Nevada
SUBSIDIARIES OF THE PARENT AND REGISTRANT
Kirby Corporate Services, LLC	Delaware
KIM Holdings, Inc.	Delaware
Kirby Terminals, Inc.	Texas
Sabine Transportation Company	Delaware
AFRAM Carriers, Inc.	Delaware
Kirby Distribution & Services, Inc.	Delaware
Kirby Tankships, Inc.	Delaware
Kirby Ocean Transport Company	Delaware
Kirby Offshore Marine, LLC	Delaware
Adaptive KRM, LLC	Texas
K Equipment, LLC	Texas
The Hollywood Camp, LLC	Texas
CONTROLLED SUBSIDIARIES
KIM Partners, LLC (Subsidiary of KIM Holdings, Inc.)	Louisiana
Kirby Inland Marine, LP (KIM Holdings, Inc. 1% General Partner, KIM Partners, LLC 99% Limited Partner)	Delaware
Greens Bayou Fleeting, LLC (subsidiary of Kirby Inland Marine, LP)	Texas
Dixie Carriers, Inc. (subsidiary of Kirby Inland Marine, LP)	Texas
Osprey Line, L.L.C. (Kirby Inland Marine, LP 66 2/3%)	Texas
San Jac Marine, LLC (subsidiary of Kirby Inland Marine, LP)	Delaware
Diesel Dash LLC (subsidiary of Kirby Distribution & Services, Inc.)	Delaware
Kirby Engine Systems LLC (subsidiary of Kirby Distribution & Services, Inc.)	Delaware
Marine Systems, Inc. (subsidiary of Kirby Engine Systems LLC)	Louisiana
Engine Systems, Inc. (subsidiary of Kirby Engine Systems LLC)	Delaware
United Holdings LLC (subsidiary of Kirby Distribution & Services, Inc.)	Delaware
United Engines LLC (subsidiary of United Holdings LLC)	Colorado
UE Manufacturing LLC (subsidiary of United Holdings LLC)	Colorado
Thermo King of Houston, LLC (subsidiary of United Holdings LLC)	Texas
Thermo King of Dallas, LLC (subsidiary of United Holdings LLC)	Texas
Thermo King of West Texas, LLC (subsidiary of United Holdings LLC)	Texas
San Antonio Thermo King, Inc. (subsidiary of Thermo King of Houston, LLC)	Texas
Kirby Offshore Marine Operating, LLC (subsidiary of Kirby Offshore Marine, LLC)	Delaware
Kirby Offshore Wind, LLC (subsidiary of Kirby Offshore Marine, LLC)	Delaware
Kirby Offshore Marine Hawaii, LLC (subsidiary of Kirby Offshore Marine Operating, LLC)	Delaware
Kirby Offshore Marine Pacific, LLC (subsidiary of Kirby Offshore Marine Operating, LLC)	Delaware
Kirby Offshore Marine, Inc. (subsidiary of Kirby Offshore Marine Operating, LLC)	Delaware
Inversiones Kara Sea SRL (subsidiary of Kirby Offshore Marine Operating, LLC)	Venezuela
K-Sea Canada Holdings, Inc. (subsidiary of Kirby Offshore Marine, Inc.)	Delaware
Penn Maritime Inc. (subsidiary of Kirby Offshore Marine, LLC)	Delaware
Stewart & Stevenson LLC (subsidiary of Kirby Distribution & Services, Inc.)	Delaware
Stewart & Stevenson Power Products LLC (subsidiary of Stewart & Stevenson LLC)	Delaware
Stewart & Stevenson Canada Inc. (subsidiary of Stewart & Stevenson LLC)	Canada
Stewart & Stevenson de las Americas Colombia Ltda. (Stewart & Stevenson Petroleum Services LLC 1% General Partner, Stewart & Stevenson LLC 99% Limited Partner)	Colombia
Stewart & Stevenson de Venezuela, S.A. (subsidiary of Stewart & Stevenson LLC 99.95%)	Venezuela
Stewart & Stevenson Petroleum Services LLC (subsidiary of Stewart & Stevenson LLC)	Delaware
Stewart & Stevenson Manufacturing Technologies LLC (subsidiary of Stewart & Stevenson LLC)	Delaware
Stewart & Stevenson Acquisition LLC (subsidiary of Stewart & Stevenson LLC)	Delaware
Stewart & Stevenson FDDA LLC (subsidiary of Stewart & Stevenson LLC)	Delaware
Transmissions Y Embragues, S.A. (subsidiary of Stewart & Stevenson de Venezuela, S.A.)	Venezuela
Stewart and Stevenson Healthcare Technologies, LLC (subsidiary of Stewart & Stevenson LLC)	Texas

Higman Marine, Inc. (subsidiary of Kirby Inland Marine, LP)	Delaware
Higman Barge Lines, Inc. (subsidiary of Higman Marine, Inc.)	Delaware
Higman Marine Services, Inc. (subsidiary of Higman Marine, Inc.)	Delaware
Higman Service Corporation (subsidiary of Higman Marine, Inc.)	Delaware
Alamo Barge Lines, LLC (subsidiary of Kirby Inland Marine, LP)	Delaware
Empty Barge Lines, Inc. (subsidiary of Kirby Inland Marine, LP)	Texas
Empty Barge Lines II, Inc. (subsidiary of Kirby Inland Marine, LP)	Texas
Empty Barge Lines III, Inc. (subsidiary of Kirby Inland Marine, LP)	Texas
EBL Marine I LLC (subsidiary of Kirby Inland Marine, LP)	Texas
EBL Marine II LLC (subsidiary of Kirby Inland Marine, LP)	Texas
EBL Marine III LLC (subsidiary of Kirby Inland Marine, LP)	Texas

EX-23.1

EXHIBIT 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the registration statements (Nos. 333-57625, 333-72592, 333-129290, 333-129333, 333-152565, 333-152566, 333-184598, 333-184599 and 333-265397) on Form S-8 and (Nos. 333-220974 and 333-222858) on Form S-3 of our reports dated February 20, 2024, with respect to the consolidated financial statements of Kirby Corporation and the effectiveness of internal control over financial reporting.

/s/ KPMG LLP

Houston, Texas

February 20, 2024

EX-31.1

EXHIBIT 31.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER

In connection with the filing of the report on Form 10-K for the year ended December 31, 2023 by Kirby Corporation, David W. Grzebinski certifies that:

1. I have reviewed this report on Form 10-K of Kirby Corporation (the “registrant”);

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

	/s/ DAVID W. GRZEBINSKI
	David W. Grzebinski
	President and Chief Executive Officer
Dated: February 20, 2024

EX-31.2

EXHIBIT 31.2

CERTIFICATION OF CHIEF FINANCIAL OFFICER

In connection with the filing of the report on Form 10-K for the year ended December 31, 2023 by Kirby Corporation, Raj Kumar certifies that:

1. I have reviewed this report on Form 10-K of Kirby Corporation (the “registrant”);

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

	/s/ RAJ KUMAR
	Raj Kumar
	Executive Vice President and
Dated: February 20, 2024	Chief Financial Officer

EX-32

EXHIBIT 32

Certification Pursuant to Section 18 U.S.C. Section 1350

(As adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002)

In connection with the filing of the Annual Report on Form 10-K for the year ended December 31, 2023 (the “Report”) by Kirby Corporation (the “Company”), each of the undersigned hereby certifies that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

	/s/ DAVID W. GRZEBINSKI
	David W. Grzebinski
	President and Chief Executive Officer
	/s/ RAJ KUMAR
	Raj Kumar
	Executive Vice President and
	Chief Financial Officer
Dated: February 20, 2024

EX-97

EXHIBIT 97

KIRBY CORPORATION
CLAWBACK POLICY

I.Introduction

The Board of Directors of the Kirby Corporation (hereinafter the “Company”) (the “Board”) believes that it is in the best interests of the Company and its shareholders to create and maintain a culture that emphasizes integrity and accountability and that reinforces the Company's pay-for- performance compensation philosophy. The Board has therefore adopted this policy which provides for the recoupment of certain executive compensation in the event of an accounting restatement resulting from material noncompliance with financial reporting requirements under the federal securities laws (the “Policy”). This Policy is designed to comply with Section 10D of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and Section 303A.14 of the New York Stock Exchange (“NYSE”) Listed Company Manual.

II.Definitions. For purposes of this policy, the terms set forth below shall have the following meanings:

(a)“Code” means the U.S. Internal Revenue Code of 1986, as amended, and the regulations and guidance thereunder.

(b)“Committee” means the Compensation Committee of the Board.

(c)“Covered Compensation” means any Incentive Compensation granted, vested, or paid to a person who served as an Executive Officer at any time during the performance period for the Incentive Compensation and that was received (i) on or after October 2, 2023, (ii) after the person became an Executive Officer, and (iii) at a time that the Company had a class of securities listed on a U.S. national securities exchange. For purposes of this Policy, Incentive Compensation is deemed “received” in the Company’s fiscal period during which the Financial Reporting Measure specified in or otherwise relating to the Incentive Compensation award is attained, even if the grant, vesting, or payment of the Incentive Compensation occurs after the end of that period.

(d)“Covered Executive” means any current and former Executive Officer subject to this Policy in accordance with its terms.

(e)“Excess Incentive Compensation” means the amount of Covered Compensation granted, vested, or paid to a person during the fiscal period when the applicable Financial Reporting Measure relating to such Covered Compensation was attained that exceeds the amount of Covered Compensation that otherwise would have been granted, vested, or paid to the person had such amount been determined based on the applicable Restatement, computed without regard to any taxes paid (i.e., on a pre-tax basis). For Covered Compensation based on stock price or total stockholder return, where the amount of Excess Incentive Compensation is not subject to mathematical recalculation directly from the information in a Restatement, the Committee will determine the amount of such Covered Compensation that constitutes Excess Incentive Compensation, if any, based on a reasonable estimate of the effect of the Restatement on the stock price or total stockholder return upon which the Covered Compensation was granted, vested, or paid and the Committee shall maintain documentation of such determination and provide such

documentation to the NYSE.

(f)“Executive Officer” means an “officer” of the Company for purposes of the reporting requirements under Section 16 of the Exchange Act.

(g)“Financial Reporting Measures” are (i) measures that are determined and presented in accordance with the accounting principles used in preparing the Company’s financial statements, (ii) any measures derived in whole or in part from such measures, (iii) stock price and (iv) total shareholder return.

(h)“Incentive Compensation” means any compensation that is granted, earned, or vested based wholly or in part upon the attainment of a Financial Reporting Measure. For purposes of this Policy, “Incentive-Based Compensation” shall also be deemed to include any amounts which were determined based on (or were otherwise calculated by reference to) Incentive Compensation (including, without limitation, any amounts under any supplemental retirement or severance plan or agreement or any notional account that is based on Incentive Compensation, as well as any earnings accrued thereon).

(i)“Lookback Period” means the three completed fiscal years (plus any transition period of less than nine months that is within or immediately following the three completed fiscal years and that results from a change in the Company’s fiscal year) immediately preceding the date on which the Company is required to prepare a Restatement for a given reporting period, with such date being the earlier of: (i) the date the Board, a committee of the Board, or the officer or officers of the Company authorized to take such action if Board action is not required, concludes, or reasonably should have concluded, that the Company is required to prepare a Restatement, or (ii) the date a court, regulator, or other legally authorized body directs the Company to prepare a Restatement. Recovery of any Excess Incentive Compensation under this Policy is not dependent on if or when the Restatement is actually filed.

(j)“Restatement” means a required accounting restatement of any Company financial statement due to the material noncompliance of the Company with any financial reporting requirement under U.S. federal securities laws, including (i) to correct an error in previously issued financial statements that is material to the previously issued financial statements or (ii) to correct an error in previously issued financial statements that is not material to the previously issued financial statements but that would result in a material misstatement if the error were corrected in the current period or left uncorrected in the current period. Recovery of any Excess Incentive Compensation under this policy is not dependent on fault, fraud, or misconduct by any person in connection with the Restatement.

For purposes of this Policy, a Restatement shall not be deemed to occur in the event of a revision of the Company’s financial statements due to an out-of-period adjustment (i.e., when the error is immaterial to the previously issued financial statements and the correction of the error is also immaterial to the current period) or a retrospective (1) application of a change in accounting principles, (2) revision to reportable segment information due to a change in the structure of the Company’s internal organization, (3) reclassification due to a discontinued operation, (4) application of a change in reporting entity, such as from a reorganization of entities under common control, or (5) revision for stock splits, reverse stock splits, stock dividends, or other changes in capital structure.

III.Statement of Policy.

In the event of a Restatement, any Excess Incentive Compensation received during the Lookback Period prior to the Restatement (a) that is then-outstanding but has not yet been paid shall be automatically and immediately forfeited and (b) that has been paid to any person shall be subject to reasonably prompt repayment to the Company. The Committee must pursue (and shall not have the discretion to waive) the forfeiture and/or repayment of such Excess Incentive Compensation, except as provided below.

2

Notwithstanding the foregoing, the Committee may determine not to pursue the forfeiture and/or recovery of Erroneously Awarded Compensation from any person if the Committee determines that such forfeiture and/or recovery would be impracticable due to any of the following circumstances: (i) the direct expense paid to a third party to assist in enforcing this policy would exceed the amount to be recovered (following reasonable attempts by the Company to recover such Excess Incentive Compensation, the documentation of such attempts, and the provision of such documentation to the NYSE); (ii) pursuing such recovery would violate the Company’s home country laws adopted prior to November 28, 2022 (provided that the Company obtains an opinion of home country counsel acceptable to the NYSE that recovery would result in such a violation and provides such opinion to the NYSE); or (iii) recovery would likely cause any otherwise tax-qualified retirement plan, under which benefits are broadly available to employees, to fail to meet the requirements of Sections 401(a)(13) or 411(a) of the Code.

Notwithstanding anything to the contrary herein, the Committee has no obligation to seek recoupment of amounts that are granted, vested, or earned based solely upon the occurrence or non-occurrence of non-financial events. Such exempt compensation includes, without limitation, base salary; time-vesting awards; compensation awarded on the basis of the achievement of metrics that are not Financial Reporting Measures; and compensation awarded solely at the discretion of the Committee, the Board, or a group composed entirely of independent members of the Board; provided that such amounts are in no way contingent on, and were not in any way granted on the basis of, the achievement of any Financial Reporting Measure.

IV.Means of Repayment.

In the event that the Committee determines that any person shall repay any Excess Incentive Compensation, the Committee shall provide written notice to such person by email or certified mail to the physical address on file with the Company for such person, and the person shall satisfy such repayment in a manner and on such terms as required by the Committee, and the Company shall be entitled to set off the repayment amount against any amount owed to the person by the Company, to require the forfeiture of any award granted by the Company to the person, or to take any and all necessary actions to reasonably promptly recoup the repayment amount from the person, in each case, to the fullest extent permitted under applicable law, including, without limitation, Section 409A of the Code. If the Committee does not specify a repayment timing in the written notice described above, the applicable person shall be required to repay the Excess Incentive Compensation to the Company by wire, cash, or cashier’s check no later than thirty (30) days after receipt of such notice.

V.No Indemnification. The Company shall not indemnify any person, directly or indirectly, for any losses that such person may incur in connection with the recovery of Excess Incentive Compensation pursuant to this Policy, including through the payment of insurance premiums or gross-up payments.

VI.Administration. This Policy and its enforcement shall be administered by the Committee. Any determinations made by the Committee under this Policy shall be final and binding on all affected persons. In the event that the Committee determines that any person shall repay any Excess Incentive Compensation, the person shall satisfy such repayment in a manner and on such terms as required by the Committee to the fullest extent permitted under applicable law including, without limitation, Section 409A of the Code.

VII.General.

(a)It is intended that this Policy be interpreted in a manner that is consistent with the requirements of Section 10D of the Exchange Act and Section 303A.14 of the NYSE Listed Company Manual. The provisions of this Policy shall be interpreted in a manner that satisfies such requirements and

3

this Policy shall be operated accordingly. If any provision of this Policy would otherwise frustrate or conflict with this intent, the provision shall be interpreted and deemed amended so as to avoid such conflict.

(b)This Policy shall be binding on and enforceable against all Executive Officers and their successors, assigns, beneficiaries or legal representatives.

(c)This Policy may be amended or terminated by the Board at any time.

(d)Any applicable award agreement or other document setting forth the terms and conditions of any compensation covered by this Policy shall be deemed to include the restrictions imposed herein and incorporate this Policy by reference and, in the event of any inconsistency, the terms of this Policy will govern.

(e)The provisions in this Policy are intended to be applied to the fullest extent of the law. To the extent that any provision of this Policy is found to be unenforceable or invalid under any applicable law, such provision will be applied to the maximum extent permitted and shall automatically be deemed amended in a manner consistent with its objectives to the extent necessary to conform to applicable law. The invalidity or unenforceability of any provision of this Policy shall not affect the validity or enforceability of any other provision of this Policy.

(f)This Policy replaces the Clawback Policy adopted by the Board on October 27, 2020 (the “Prior Policy”). The rights of the Company under this Policy to seek forfeiture or reimbursement are in addition to, and not in lieu of, any rights of recoupment, or remedies or rights other than recoupment, that may be available to the Company pursuant to the terms of any law, government regulation, or stock exchange listing requirement or any other policy, plan, or agreement of the Company; provided, however, that any amounts recouped under any other policy that would be recoupable under this Policy shall count toward any required recoupment under this Policy and vice versa. For avoidance of doubt, any Excess Incentive Compensation (within the meaning of the Prior Policy) received prior to October 2, 2023, shall be subject to the terms of the Prior Policy.

Adopted: October 24, 2023

4

XML

Document and Entity Information - USD ($)
$ in Billions

12 Months Ended

Dec. 31, 2023

Feb. 16, 2024

Jun. 30, 2023

Cover [Abstract]

Entity Registrant Name

Kirby Corporation

Entity Central Index Key

0000056047

Current Fiscal Year End Date

--12-31

Document Type

10-K

Amendment Flag

false

Document Annual Report

true

Document Period End Date

Dec. 31, 2023

Document Fiscal Year Focus

2023

Document Fiscal Period Focus

FY

Document Transition Report

false

Securities Act File Number

1-07615

Entity Incorporation, State or Country Code

NV

Entity Tax Identification Number

74-1884980

Entity Address, Address Line One

55 Waugh Drive

Entity Address, Address Line Two

Suite 1000

Entity Address, City or Town

Houston

Entity Address, State or Province

TX

Entity Address, Postal Zip Code

77007

City Area Code

713

Local Phone Number

435-1000

Title of 12(b) Security

Common Stock

Trading Symbol

KEX

Security Exchange Name

NYSE

Entity Well-known Seasoned Issuer

Yes

Entity Voluntary Filers

No

Entity Current Reporting Status

Yes

Entity Interactive Data Current

Yes

Entity Filer Category

Large Accelerated Filer

ICFR Auditor Attestation Flag

true

Entity Small Business

false

Entity Emerging Growth Company

false

Entity Shell Company

false

Entity Public Float

$ 4.5

Entity Common Stock, Shares Outstanding

58,522,000

Documents Incorporated by Reference [Text Block]

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the Company’s definitive proxy statement in connection with the Annual Meeting of Stockholders to be held April 26, 2024, to be filed with the Commission pursuant to Regulation 14A, and the related annual report for the fiscal year ended December 31, 2023, to be provided to the Company's stockholders pursuant to Rule 14a-3(b) are incorporated by reference into Parts II and III of this report.

Auditor Name

KPMG LLP

Auditor Location

Houston, TX

Auditor Firm ID

185

Document Financial Statement Error Correction [Flag]

false

XML

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 32,577	$ 80,577
Accounts receivable:
Trade - less allowance for doubtful accounts of $7,636 ($7,684 in 2022)	526,691	483,406
Other	52,025	114,556
Inventories - net	454,389	461,848
Prepaid expenses and other current assets	69,479	71,372
Total current assets	1,135,161	1,211,759
Property and equipment - net	3,861,105	3,633,462
Operating lease right-of-use assets	152,216	154,507
Investment in affiliates	2,576	2,171
Goodwill	438,748	438,748
Other intangibles, net	42,927	51,463
Other assets	89,464	62,814
Total assets	5,722,197	5,554,924
Current liabilities:
Bank notes payable	8,068	3,292
Income taxes payable	1,486	323
Accounts payable	269,378	278,081
Accrued liabilities:
Interest	13,114	11,630
Insurance premiums and claims	84,825	65,088
Employee compensation	69,075	55,851
Taxes - other than on income	31,555	30,169
Other	30,377	42,014
Current portion of operating lease liabilities	33,340	36,444
Deferred revenues	134,577	119,305
Total current liabilities	675,795	642,197
Long-term debt, net - less current portion	1,008,527	1,076,326
Deferred income taxes	696,557	625,884
Operating lease liabilities - less current portion	138,811	142,140
Other long-term liabilities	15,830	23,209
Total long-term liabilities	1,859,725	1,867,559
Contingencies and commitments	0	0
Kirby stockholders' equity:
Common stock, $0.10 par value per share. Authorized 120,000,000 shares, issued 65,472,000	6,547	6,547
Additional paid-in capital	863,963	859,345
Accumulated other comprehensive income - net	35,006	16,853
Retained earnings	2,691,665	2,468,730
Treasury stock - at cost, 6,843,000 shares in 2023 and 5,565,000 shares in 2022	(411,750)	(308,598)
Total Kirby stockholders' equity	3,185,431	3,042,877
Noncontrolling interests	1,246	2,291
Total equity	3,186,677	3,045,168
Total liabilities and equity	$ 5,722,197	$ 5,554,924

XML

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets, Current [Abstract]
Trade, allowance for doubtful accounts	$ 7,636	$ 7,684
Equity, Attributable to Parent [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Common Stock, Shares Authorized	120,000,000	120,000,000
Common Stock, Shares, Issued	65,472,000	65,472,000
Treasury Stock, Common, Shares	6,843,000	5,565,000

XML

CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues [Abstract]
Revenues	$ 3,091,640	$ 2,784,754	$ 2,246,660
Costs and expenses:
Costs of sales and operating expenses	2,180,422	2,060,941	1,652,961
Selling, General and Administrative Expense	335,213	302,692	266,911
Taxes, other than on income	34,766	35,071	36,251
Depreciation, Depletion and Amortization	211,156	201,443	213,718
Impairments and other charges	0	0	340,713
Gain on disposition of assets	(5,009)	(8,279)	(5,761)
Total costs and expenses	2,756,548	2,591,868	2,504,793
Operating income (loss)	335,092	192,886	(258,133)
Other income	11,041	16,677	10,001
Interest expense	(52,008)	(44,588)	(42,469)
Earnings (loss) before taxes on income	294,125	164,975	(290,601)
(Provision) benefit for taxes on income	(71,220)	(42,214)	43,830
Net earnings (loss)	222,905	122,761	(246,771)
Less: Net (earnings) loss attributable to noncontrolling interests	30	(470)	(183)
Net earnings (loss) attributable to Kirby	$ 222,935	$ 122,291	$ (246,954)
Net earnings (loss) per share attributable to Kirby common stockholders:
Earnings Per Share, Basic	$ 3.74	$ 2.04	$ (4.11)
Earnings Per Share, Diluted	$ 3.72	$ 2.03	$ (4.11)
Marine Transportation [Member]
Revenues [Abstract]
Revenues	$ 1,721,937	$ 1,616,967	$ 1,322,918
Distribution and Services [Member]
Revenues [Abstract]
Revenues	$ 1,369,703	$ 1,167,787	$ 923,742

XML

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ 222,905	$ 122,761	$ (246,771)
Other comprehensive income , net of taxes:
Pension and postretirement benefits	16,728	43,868	36,547
Foreign currency translation adjustments	1,425	(1,049)	(1,061)
Total other comprehensive income , net of taxes	18,153	42,819	35,486
Total comprehensive income (loss), net of taxes	241,058	165,580	(211,285)
Net (earnings) loss attributable to noncontrolling interests	30	(470)	(183)
Comprehensive income (loss) attributable to Kirby	$ 241,088	$ 165,110	$ (211,468)

XML

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net earnings (loss)	$ 222,905	$ 122,761	$ (246,771)
Adjustments to reconcile net earnings (loss) to net cash provided by operations:
Depreciation and amortization	211,156	201,443	213,718
Provision (credit) for doubtful accounts	402	1,183	(138)
Provision (benefit) for deferred income taxes	65,298	37,782	(44,419)
Gain on disposition of assets	(5,009)	(8,279)	(5,761)
Impairments and other charges	0	0	340,713
Amortization of share-based compensation	14,941	13,865	15,713
Amortization of major maintenance costs	28,966	29,031	33,213
Other	(3,338)	(283)	(640)
Increase (decrease) in cash flows resulting from changes in:
Accounts receivable	(50,135)	(31,550)	29,126
Inventory	7,694	(127,095)	(19,248)
Other assets	(37,688)	(27,801)	(38,335)
Income taxes payable	71,604	1,975	480
Accounts payable	(18,271)	75,996	15,951
Accrued and other liabilities	31,703	5,100	27,974
Net cash provided by operating activities	540,228	294,128	321,576
Cash flows from investing activities:
Capital expenditures	(401,730)	(172,606)	(98,015)
Acquisitions of businesses and marine equipment, net of cash acquired	(37,500)	(3,900)	(9,115)
Proceeds from disposition of assets and other	26,081	36,905	51,342
Net cash used in investing activities	(413,149)	(139,601)	(55,788)
Cash flows from financing activities:
Borrowings (payments) on bank credit facilities, net	48,776	1,358	(248,105)
Borrowings on long-term debt	240,000	310,000	0
Payments on long-term debt	(350,000)	(395,000)	(60,000)
Payment of debt issue costs	(1,254)	(1,977)	0
Proceeds from exercise of stock options	4,209	3,887	629
Payments related to tax withholding for share-based compensation	(3,908)	(3,408)	(2,856)
Treasury stock purchases	(112,803)	(22,901)	0
Return of investment to noncontrolling interests and other	(99)	(722)	(981)
Net cash used in financing activities	(175,079)	(108,763)	(311,313)
Increase (decrease) in cash and cash equivalents	(48,000)	45,764	(45,525)
Cash and cash equivalents, beginning of year	80,577	34,813	80,338
Cash and cash equivalents, end of year	32,577	80,577	34,813
Cash paid (received) during the period:
Interest paid	49,317	42,816	40,878
Income taxes paid (refunded), net	(65,787)	2,553	(116,648)
Operating cash outflow from operating leases	43,954	44,229	44,089
Non-cash investing activity:
Capital expenditures included in accounts payable	9,567	2,996	18,633
Right-of-use assets obtained in exchange for lease obligations	$ 39,153	$ 22,799	$ 33,842

XML

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]	Treasury Stock Common [Member]	Noncontrolling Interests [Member]
Beginning balance at Dec. 31, 2020	$ 3,087,553	$ 6,547	$ 844,979	$ (61,452)	$ 2,593,393	$ (299,161)	$ 3,247
Beginning balance (in shares) at Dec. 31, 2020		65,472,000				(5,434,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises	629		21			$ 608
Stock option exercises (in shares)						12,000
Issuance of stock for equity awards, net of forfeitures			(6,201)			$ 6,201
Issuance of stock for equity awards, net of forfeitures (in shares)						113,000
Tax withholdings on equity award vesting	(2,856)					$ (2,856)
Tax withholdings on equity award vesting (in shares)						(52,000)
Amortization of share-based compensation	15,713		15,713
Total comprehensive income (loss), net of taxes	(211,285)			35,486	(246,954)		183
Return of investment to noncontrolling interests	(972)						(972)
Ending balance at Dec. 31, 2021	2,888,782	$ 6,547	854,512	(25,966)	2,346,439	$ (295,208)	2,458
Ending balance (in shares) at Dec. 31, 2021		65,472,000				(5,361,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises	3,887		757			$ 3,130
Stock option exercises (in shares)						58,000
Issuance of stock for equity awards, net of forfeitures			(9,789)			$ 9,789
Issuance of stock for equity awards, net of forfeitures (in shares)						178,000
Tax withholdings on equity award vesting	(3,408)					$ (3,408)
Tax withholdings on equity award vesting (in shares)						(54,000)
Amortization of share-based compensation	13,865		13,865
Treasury stock purchases	(22,901)					$ (22,901)
Treasury stock purchases (in shares)						(386,000)
Total comprehensive income (loss), net of taxes	165,580			42,819	122,291		470
Return of investment to noncontrolling interests	(637)						(637)
Ending balance at Dec. 31, 2022	3,045,168	$ 6,547	859,345	16,853	2,468,730	$ (308,598)	2,291
Ending balance (in shares) at Dec. 31, 2022		65,472,000				(5,565,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises	4,208		453			$ 3,755
Stock option exercises (in shares)						71,000
Issuance of stock for equity awards, net of forfeitures			(10,776)			$ 10,776
Issuance of stock for equity awards, net of forfeitures (in shares)						194,000
Tax withholdings on equity award vesting	(3,908)					$ (3,908)
Tax withholdings on equity award vesting (in shares)						(58,000)
Amortization of share-based compensation	14,941		14,941
Treasury stock purchases	(112,803)					$ (112,803)
Treasury stock purchases (in shares)						(1,485,000)
Excise taxes on treasury stock purchases	(972)					$ (972)
Total comprehensive income (loss), net of taxes	241,058			18,153	222,935		(30)
Return of investment to noncontrolling interests	(1,015)						(1,015)
Ending balance at Dec. 31, 2023	$ 3,186,677	$ 6,547	$ 863,963	$ 35,006	$ 2,691,665	$ (411,750)	$ 1,246
Ending balance (in shares) at Dec. 31, 2023		65,472,000				(6,843,000)

XML

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss)	$ 222,935	$ 122,291	$ (246,954)

XML

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

XML

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

(1) Summary of Significant Accounting Policies

Principles of Consolidation. The consolidated financial statements include the accounts of Kirby Corporation and all majority-owned subsidiaries (the “Company”). All investments in which the Company owns 20% to 50% and exercises significant influence over operating and financial policies are accounted for using the equity method. All material intercompany accounts and transactions have been eliminated in consolidation. Certain reclassifications have been made to reflect the current presentation of financial information. Such reclassifications have no impact on previously reported net earnings (loss), stockholders’ equity, or cash flows.

Accounting Policies

Cash Equivalents. Cash equivalents consist of all short-term, highly liquid investments with maturities of three months or less at date of purchase.

Accounts Receivable. In the normal course of business, the Company extends credit to its customers. The Company regularly reviews the accounts and makes adequate provisions for probable uncollectible balances. It is the Company’s opinion that the accounts have no impairment, other than that for which provisions have been made. Included in accounts receivable-trade as of December 31, 2023 and 2022 were $136.3 million and $139.5 million, respectively, of accruals for revenues earned which have not been invoiced as of the end of each year.

Accrued Insurance. The Company’s marine transportation and distribution and services operations are subject to hazards associated with such businesses. The marine transportation business in particular is subject to property damage and casualty risks associated with operating vessels carrying large volumes of bulk liquid and dry cargo in a marine environment. The Company maintains insurance coverage against these hazards with insurance companies subject to a deductible, below which the Company is liable. The Company uses historic experience and actuarial analysis by outside consultants to estimate an appropriate level of accrued insurance liabilities including estimates on individual claims outstanding and an estimated amount for losses that may have occurred but have not been reported to the Company (“IBNR”) or not yet fully developed. If the actual number of claims and magnitude were substantially greater than assumed, the required level of accrued liabilities for claims incurred but not reported or fully developed could be materially understated. Insurance premiums, IBNR losses and incurred claim losses, up to the Company’s deductible for the years ended December 31, 2023, 2022, and 2021, were $52.5 million, $39.1 million, and $37.8 million, respectively.

The Company records receivables from its insurers for incurred claims above the Company’s deductible. If the solvency of the insurers becomes impaired, there could be an adverse impact on the accrued receivables and the availability of insurance. Included in accounts receivable-other as of December 31, 2023 and 2022 were $29.6 million and $27.7 million, respectively, of receivables from insurance companies to cover claims in excess of the Company’s deductible.

Concentrations of Credit Risk. Financial instruments which potentially subject the Company to concentrations of credit risk are primarily trade accounts receivables. The Company’s marine transportation customers include the major oil refining and petrochemical companies. The distribution and services customers are oilfield service companies, oil and gas operators and producers, on-highway transportation companies, marine transportation companies, commercial fishing companies, construction companies, power generation companies, and the United States government. The Company regularly reviews its accounts and estimates the amount of uncollectible receivables each period and establishes an allowance for uncollectible amounts. The amount of the allowance is based on the age of unpaid amounts, information about the current financial strength of customers, and other relevant information. Estimates of uncollectible amounts are revised each period, and changes are recorded in the period they become known.

Historically, credit risk with respect to these trade receivables has generally been considered minimal because of the financial strength of the Company’s customers; however, a United States or global recession or other adverse economic condition could impact the collectability of certain customers’ trade receivables which could have a material effect on the Company’s results of operations.

Inventories. Inventories are stated at the lower of average cost or net realizable value.

Property, Maintenance and Repairs. Property is recorded at cost or acquisition date fair value; improvements and betterments are capitalized as incurred. Depreciation is recorded using the straight-line method over the estimated useful lives of the individual assets as follows: marine transportation equipment, 5-40 years; buildings, 10-40 years; other equipment, 2-10 years; and leasehold improvements, term of lease. When property items are retired, sold, or otherwise disposed of, the related cost and accumulated depreciation are removed from the accounts with any gain or loss on the disposition included in the statement of earnings. Maintenance and repairs on vessels built for use on the inland waterways are charged to operating expense as incurred and includes the costs incurred

in United States Coast Guard (“USCG”) inspections unless the shipyard extends the life, improves the operating capacity, or replaces significant components of the vessel, which results in the costs being capitalized.

The following table summarizes the balances of property and equipment – net (in thousands):

	December 31,
	2023			2022
Land	$	39,567		$	38,551
Marine transportation equipment		5,029,653			4,837,379
Buildings and other equipment		641,871			505,942
Construction in progress		112,947			70,271
	$	5,824,038		$	5,452,143
Accumulated depreciation		(1,962,933	)		(1,818,681	)
Property and equipment – net	$	3,861,105		$	3,633,462

Drydocking on Ocean-Going Vessels. The Company’s ocean-going vessels are subject to regulatory drydocking requirements after certain periods of time to be inspected, have planned major maintenance performed and be recertified by the American Bureau of Shipping (“ABS”). These recertifications generally occur twice in a five-year period. The Company defers the drydocking expenditures incurred on its ocean-going vessels due to regulatory marine inspections by the ABS and amortizes the costs of the shipyard over the period between drydockings, generally 30 or 60 months, depending on the type of major maintenance performed. Drydocking expenditures that extend the life, improve the operating capability, or replace significant components of the vessel are capitalized. The Company recognized amortization of major maintenance costs of $29.0 million, $29.0 million, and $33.2 million for the years ended December 31, 2023, 2022, and 2021, respectively, in costs of sales and operating expenses. Routine repairs and maintenance on ocean-going vessels are expensed as incurred. Interest is capitalized on the construction of new ocean-going vessels. For the years ended December 31, 2023, 2022 and 2021, no interest was capitalized.

Environmental Liabilities. The Company expenses costs related to environmental events as they are incurred or when a loss is considered probable and reasonably estimable.

Goodwill. The excess of the purchase price over the fair value of identifiable net assets acquired in transactions accounted for as a purchase is included in goodwill. The Company conducted its annual goodwill impairment tests at November 30, 2023, 2022, and 2021. The Company also conducted an interim goodwill impairment test at September 30, 2021. Refer to Note 7, Impairments and other charges for more information. The Company will continue to conduct goodwill impairment tests as of November 30 of subsequent years, or whenever events or circumstances indicate that interim impairment testing is necessary. The amount of goodwill impairment, if any, is typically measured based on a combination of projected discounted future operating cash flows using an appropriate discount rate and a market approach for comparable companies. The following table summarizes the changes in goodwill (in thousands):

	Marine Transportation			Distribution and Services			Total
Balance at December 31, 2022 (gross)		505,784			560,155			1,065,939
Accumulated impairment and amortization		(237,626	)		(389,565	)		(627,191	)
Balance at December 31, 2022 and 2023	$	268,158		$	170,590		$	438,748

Other Intangibles. Other intangibles include assets for favorable contracts and customer relationships, distributorship and dealership agreements, trade names and non-compete agreements and liabilities for unfavorable leases and contracts. The following table summarizes the balances of other intangible assets and other intangible liabilities (in thousands):

	December 31,
	2023			2022
Other intangible assets – gross	$	184,622		$	203,242
Accumulated amortization		(141,695	)		(151,779	)
Other intangible assets – net	$	42,927		$	51,463
Other intangible liabilities – gross	$	8,800		$	13,860
Accumulated amortization		(8,800	)		(13,280	)
Other intangible liabilities – net	$	—		$	580

The costs of intangible assets and liabilities are amortized to expense in a systematic and rational manner over their estimated useful lives. For the years ended December 31, 2023, 2022, and 2021, the amortization expense for intangibles was $8.1 million, $7.6 million, and $7.8 million, respectively. Estimated net amortization expense for amortizable intangible assets and liabilities for the next five years

(2024 – 2028) is approximately $8.5 million, $8.5 million, $6.3 million, $5.0 million, and $3.5 million, respectively, and $11.1 million thereafter. As of December 31, 2023, the weighted average amortization period for intangible assets and liabilities was approximately seven years.

Revenue Recognition. The majority of marine transportation revenue is derived from term contracts, ranging from one to three years, some of which have renewal options, and the remainder is from spot contracts. The majority of the term contracts by revenue are for terms of one year. The Company provides marine transportation services for its customers and, in almost all cases, does not assume ownership of the products it transports. The Company enters into agreements with its customers to transport cargo from a designated origin to a designated destination at a set rate (affreightment) or at a daily rate (time charter). The rate may or may not escalate during the term of the contract, however, the base rate generally remains constant and contracts often include escalation provisions to recover changes in specific costs such as fuel. Time charter or contracts of affreightment of one year or greater are considered term contract revenues and agreements of less than a year are included in spot contract revenues. Spot contracts typically involve an agreement with a customer to move cargo from a specific origin to a designated destination for a rate generally negotiated at the time the cargo movement takes place. Spot contract rates are typically at the current “market” rate, including fuel, and are subject to market volatility. The Company uses a voyage accounting method of revenue recognition for its marine transportation revenues which allocates voyage revenue based on the percent of the voyage completed during the period. The performance of the service is invoiced as the transaction occurs and payment is required depending on each specific customer’s credit.

Distribution products and services are generally sold based upon purchase orders or preferential service agreements with the customer that include fixed or determinable prices. Parts sales are recognized when control transfers to the customer, generally when title passes upon shipment to customers. Service revenue is recognized over time as the service is provided using measures of progress utilizing hours worked or costs incurred as a percentage of estimated hours or expected costs. Revenue from rental agreements is generally recognized on a straight-line basis over the rental period. The Company recognizes the revenues on manufacturing activities upon shipment and transfer of control to the customer. The transactions in the distribution and services segment (“KDS”) are typically invoiced as parts are shipped or upon the completion of the service job. Contract manufacturing activities are generally invoiced upon shipment and the Company will often get deposits from its customers prior to starting work, or progress payments during the project depending on the credit worthiness of the customer and the size of the project.

Stock-Based Compensation. The Company has share-based compensation plans covering selected officers and other key employees as well as the Company’s Board of Directors. Stock-based grants made under the Company’s stock plans are measured at fair value on the date of the grant and the cost for all grants made under the director plan and for grants made under the employee plan is generally recognized ratably over the vesting period of the restricted stock unit (“RSU”), stock option, or restricted stock. The employee plan, however, includes a provision for the continued vesting of unvested stock options and RSUs for employees who meet certain years of service and age requirements at the time of their retirement. The provision results in shorter expense accrual periods on stock options and RSUs granted to employees who are nearing retirement and meet the service and age requirements. Stock option grants are valued at the date of grant as calculated under the Black-Scholes option pricing model. The Company accounts for forfeitures as they occur. The Company’s stock-based compensation plans are more fully described in Note 8, Stock Award Plans.

Taxes on Income. The Company follows the asset and liability method of accounting for income taxes. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

Treasury Stock. The Company follows the average cost method of accounting for treasury stock transactions.

Impairment of Long-lived Assets and for Long-lived Assets to Be Disposed Of. The Company performs an impairment assessment whenever events or changes in circumstances indicate that the carrying amount of long-lived assets may not be recoverable.

Recoverability on marine transportation assets is assessed based on vessel classes, not on individual assets, because identifiable cash flows for individual marine transportation assets are not available. Projecting customer contract volumes allows estimation of future cash flows by projecting pricing and utilization by vessel class but it is not practical to project which individual marine transportation asset will be utilized for any given contract. Because customers generally do not specify which particular vessel is used, prices are quoted based on vessel classes not individual assets. Nominations of vessels for specific jobs are determined on a day by day basis and are a function of the equipment class required and the geographic position of vessels within that class at that particular time as vessels within a class are interchangeable and provide the same service. The Company’s vessels are mobile assets and equipped to operate in geographic regions throughout the United States and the Company has in the past and expects to continue to move vessels from one region to another when it is necessary due to changing markets and it is economical to do so. Barge vessel classes are based on similar capacities, hull type, and type of product and towing vessels are based on similar hull type and horsepower.

If a triggering event is identified, the Company compares the carrying amount of the asset group to the estimated undiscounted future cash flows expected to result from the use of the asset group. If the carrying amount of the asset group exceeds the estimated undiscounted future cash flows, the Company measures the amount of the impairment by comparing the carrying amount of the asset group to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell.

Fair Value Measurements. The accounting guidance for using fair value to measure certain assets and liabilities establishes a three tier value hierarchy, which prioritizes the inputs to valuation techniques used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little, if any, market data exists, therefore requiring an entity to develop its own assumptions about the assumptions that market participants would use in pricing the asset or liability. The fair value of the Company’s debt instruments is described in Note 5, Long-Term Debt.

Accounting Standards

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”) which requires entities to disclose additional information in specified categories with respect to the reconciliation of the effective tax rate to the statutory rate for federal, state, and foreign income taxes. ASU 2023-09 is effective for annual and interim periods beginning after December 15, 2023, with early adoption permitted. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements.

In November 2023, the FASB issued ASU No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”) to improve reportable segment disclosure requirements. The amendments require disclosure of significant segment expenses regularly provided to the chief operating decision maker (“CODM”) as well as other segment items, extend certain annual disclosures to interim periods, clarify the applicability to single reportable segment entities, permit more than one measure of profit or loss to be reported under certain conditions, and require disclosure of the title and position of the CODM. ASU 2023-07 is effective for annual periods beginning after December 15, 2024 and for interim periods beginning after December 15, 2025, with early adoption permitted. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements.

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Acquisitions

12 Months Ended

Dec. 31, 2023

Business Combinations [Abstract]

Acquisitions

(2) Acquisitions

On July 14, 2023, the Company purchased 23 inland tank barges with a total capacity of 265,000 barrels from an undisclosed seller for $37 million in cash. The 23 tank barges transport petrochemicals and refined products on the Mississippi River System and the Gulf Intracoastal Waterway. The average age of the 23 barges was 14 years.

The Company purchased four inland tank barges from a leasing company for $0.5 million in cash during the 2023 third quarter. The Company had been leasing the barges prior to the purchase.

On March 31, 2022, the Company paid $3.9 million in cash to purchase assets of a gearbox repair company in KDS. Assets acquired consisted primarily of property and equipment.

The Company purchased four inland tank barges from a leasing company for $7.5 million in cash during 2021. The Company had been leasing the barges prior to the purchase.

On October 4, 2021, the Company paid $1.6 million in cash to purchase assets of an energy storage systems manufacturer based in Texas which have been key to the development of new power generation solutions for electric fracturing equipment. Assets acquired and liabilities assumed consisted primarily of a right of use lease asset and lease liability for an operating lease assumed as part of the acquisition.

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Revenues

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Revenues

(3) Revenues

The following table sets forth the Company’s revenues by major source (in thousands):

	Year Ended December 31,
	2023		2022		2021
Marine transportation segment:
Inland transportation	$	1,416,483	$	1,277,010	$	1,005,145
Coastal transportation		305,454		339,957		317,773
	$	1,721,937	$	1,616,967	$	1,322,918
Distribution and services segment:
Commercial and industrial	$	802,474	$	651,566	$	578,011
Oil and gas		567,229		516,221		345,731
	$	1,369,703	$	1,167,787	$	923,742

The Company’s revenue is measured based on consideration specified in its contracts with its customers. The Company recognizes revenue over time as it provides services to its customers, or at the point in time that control over a part or product transfers to its customer.

Contract Assets and Liabilities. Contract liabilities represent advance consideration received from customers, and are recognized as revenue over time or at a point in time as the related performance obligation is satisfied. Revenues recognized during the years ended December 31, 2023, 2022, and 2021, that were included in the opening contract liability balances were $84.0 million, $61.7 million and $40.9 million, respectively. The Company has recognized all contract liabilities within the deferred revenues financial statement caption on the balance sheet. The Company did not have any contract assets at December 31, 2023 or December 31, 2022. The Company applies the practical expedient that allows non-disclosure of information about remaining performance obligations that have original expected durations of one year or less.

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Segment Data

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

Segment Data

(4) Segment Data

The Company’s operations are aggregated into two reportable business segments as follows:

Marine Transportation — Provides marine transportation by United States flagged vessels principally of liquid cargoes throughout the United States inland waterway system, along all three United States coasts, and to a lesser extent, in United States coastal transportation of dry-bulk cargoes. The principal products transported include petrochemicals, black oil, refined petroleum products and agricultural chemicals.

Distribution and Services — Provides after-market services and genuine replacement parts for engines, transmissions, reduction gears and related equipment used in oilfield services, marine, power generation, on-highway, and other industrial applications. The Company also rents equipment including generators, industrial compressors, high capacity lift trucks, and refrigeration trailers for use in a variety of industrial markets, and manufactures and remanufactures oilfield service equipment, including pressure pumping units, electric power generation equipment, specialized electrical distribution and control equipment, and high capacity energy storage/battery systems for oilfield service and railroad customers.

The Company’s two reportable business segments are managed separately based on fundamental differences in their operations. The Company’s accounting policies for the business segments are the same as those described in Note 1, Summary of Significant Accounting Policies. The Company evaluates the performance of its segments based on the contributions to operating income of the respective segments, and before income taxes, interest, gains or losses on disposition of assets, other nonoperating income, noncontrolling interests, accounting changes, and nonrecurring items. Intersegment revenues, based on market-based pricing, of KDS from KMT of $39.8 million, $31.9 million, and $23.6 million in 2023, 2022, and 2021, respectively, as well as the related intersegment profit of $4.0 million, $3.2 million, and $2.4 million in 2023, 2022, and 2021, respectively, have been eliminated from the tables below.

The following tables set forth by reportable segment the revenues, profit or loss, total assets, depreciation and amortization, and capital expenditures attributable to the principal activities of the Company (in thousands):

	Year Ended December 31,
	2023			2022			2021
Revenues:
Marine transportation	$	1,721,937		$	1,616,967		$	1,322,918
Distribution and services		1,369,703			1,167,787			923,742
	$	3,091,640		$	2,784,754		$	2,246,660
Segment profit (loss):
Marine transportation	$	238,943		$	136,184		$	63,015
Distribution and services		114,481			67,037			27,607
Other		(59,299	)		(38,246	)		(381,223	)
	$	294,125		$	164,975		$	(290,601	)
Depreciation and amortization:
Marine transportation	$	184,225		$	177,551		$	185,979
Distribution and services		19,842			16,776			20,573
Other		7,089			7,116			7,166
	$	211,156		$	201,443		$	213,718
Capital expenditures:
Marine transportation	$	255,411		$	147,170		$	84,353
Distribution and services		140,769			21,713			8,104
Other		5,550			3,723			5,558
	$	401,730		$	172,606		$	98,015

	December 31,
	2023		2022
Total assets:
Marine transportation	$	4,454,931	$	4,285,647
Distribution and services		1,156,384		1,041,841
Other		110,882		227,436
	$	5,722,197	$	5,554,924

The following table presents the details of “Other” segment profit (loss) (in thousands):

	Year Ended December 31,
	2023			2022			2021
General corporate expenses	$	(23,341	)	$	(18,614	)	$	(13,803	)
Gain on disposition of assets		5,009			8,279			5,761
Impairments and other charges		—			—			(340,713	)
Interest expense		(52,008	)		(44,588	)		(42,469	)
Other income		11,041			16,677			10,001
	$	(59,299	)	$	(38,246	)	$	(381,223	)

The following table presents the details of “Other” total assets (in thousands):

	December 31,
	2023		2022
General corporate assets	$	108,306	$	225,265
Investment in affiliates		2,576		2,171
	$	110,882	$	227,436

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Long-Term Debt

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Long-Term Debt

(5) Long-Term Debt

The following table presents the carrying value and fair value (determined using inputs characteristic of a Level 2 fair value measurement) of debt outstanding (in thousands):

	December 31,
	2023					2022
	Carrying Value			Fair Value		Carrying Value			Fair Value
Revolving Credit Facility due July 29, 2027 (a)	$	44,000		$	44,000	$	—		$	—
Term Loan due July 29, 2027 (a)		170,000			170,000		170,000			170,000
3.29% senior notes due February 27, 2023		—			—		350,000			352,275
4.2% senior notes due March 1, 2028		500,000			475,920		500,000			477,660
3.46% senior notes due January 19, 2033		60,000			49,955		60,000			42,647
3.51% senior notes due January 19, 2033		240,000			200,698		—			—
Credit Line due June 30, 2024		—			—		—			—
Bank notes payable		8,068			8,068		3,292			3,292
		1,022,068			948,641		1,083,292			1,045,874
Unamortized debt discounts and issuance costs (b)		(5,473	)		—		(3,674	)		—
	$	1,016,595		$	948,641	$	1,079,618		$	1,045,874

(a)Variable interest rate of 6.8% and 5.8% at December 31, 2023 and 2022, respectively.

(b)Excludes $1.8 million attributable to the 2027 Revolving Credit Facility included in other assets at December 31, 2022.

The aggregate payments due on the long-term debt in each of the next five years were as follows (in thousands):

2024	$	8,068
2025		32,500
2026		56,250
2027		125,250
2028		500,000
Thereafter		300,000
	$	1,022,068

At the beginning of 2022, the Company had an amended and restated credit agreement (the “2024 Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank, that allowed for an $850 million unsecured revolving credit facility (the “2024 Revolving Credit Facility”) and an unsecured term loan (the “2024 Term Loan”) with a maturity date of March 27, 2024. The 2024 Term Loan was prepayable, in whole or in part, without penalty.

On July 29, 2022, the Company entered into a new credit agreement (the “2027 Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank that allows for a $500 million unsecured revolving credit facility (the “2027 Revolving Credit Facility”) and a $250 million unsecured term loan (the “2027 Term Loan”) with a maturity date of July 29, 2027. The 2027 Credit Agreement replaced the 2024 Credit Agreement. In conjunction with entering into the 2027 Credit Agreement, on July 29, 2022, the Company borrowed $35 million under the 2027 Revolving Credit Facility and $250 million under the 2027 Term Loan to repay borrowings under the 2024 Term Loan. In the fourth quarter of 2022, the Company repaid $80.0 million under the 2027 Term Loan prior to scheduled maturities. As a result, no repayments are required until June 30, 2025. Outstanding letters of credit under the 2027 Revolving Credit Facility were $6,000 and available borrowing capacity was $456.0 million as of December 31, 2023.

The 2027 Term Loan is repayable in quarterly installments, with no repayments until June 30, 2025, in increasing percentages of the original principal amount of the loan, with the remaining unpaid balance of approximately $43.8 million payable upon maturity, assuming no prepayment. The 2027 Term Loan is prepayable, in whole or in part, without penalty. The 2027 Credit Agreement provides for a variable interest rate based on the Secured Overnight Financing Rate (“SOFR”) or a base rate calculated with reference to the prime rate quoted by The Wall Street Journal, the Federal Reserve Bank of New York Rate plus 0.5%, or the adjusted SOFR rate for a one month interest period plus 1.0%, among other factors (the “Alternate Base Rate”). The interest rate varies with the Company’s credit rating and is currently 137.5 basis points over SOFR or 37.5 basis points over the Alternate Base Rate. The 2027 Credit Agreement contains certain financial covenants including an interest coverage ratio and debt-to-capitalization ratio. In addition to financial covenants, the 2027 Credit Agreement contains covenants that, subject to exceptions, restrict debt incurrence, mergers and acquisitions, sales of assets, dividends and investments, liquidations and dissolutions, capital leases, transactions with affiliates, and changes in lines of business. The 2027 Credit Agreement specifies certain events of default, upon the occurrence of which the maturity of the outstanding loans may be accelerated, including the failure to pay principal or interest, violation of covenants and default on other indebtedness,

among other events. Borrowings under the 2027 Credit Agreement may be used for general corporate purposes including acquisitions. The 2027 Revolving Credit Facility includes a $25 million commitment which may be used for standby letters of credit.

The Company has $500 million of 4.2% senior unsecured notes due March 1, 2028 (the “2028 Notes”) with U.S. Bank National Association, as trustee. No principal payments are required until maturity. Interest payments of $10.5 million are due semi-annually on March 1 and September 1 of each year. The 2028 Notes are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. The 2028 Notes contain certain covenants on the part of the Company, including covenants relating to liens, sale-leasebacks, asset sales and mergers, among others. The 2028 Notes also specify certain events of default, upon the occurrence of which the maturity of the notes may be accelerated, including failure to pay principal and interest, violation of covenants or default on other indebtedness, among others.

On February 3, 2022, the Company entered into a note purchase agreement for the issuance of $300 million of unsecured senior notes with a group of institutional investors, consisting of $60 million of 3.46% series A notes (“Series A Notes”) and $240 million of 3.51% series B notes (“Series B Notes”), each due January 19, 2033 (collectively, the “2033 Notes”). The Series A Notes were issued on October 20, 2022, and the Series B Notes were issued on January 19, 2023. No principal payments will be required until maturity. Beginning in 2023, interest payments of $5.3 million are due semi-annually on January 19 and July 19 of each year, with the exception of the first payment on January 19, 2023, which was $0.5 million. The 2033 Notes are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. The 2033 Notes contain certain covenants on the part of the Company, including an interest coverage covenant, a debt-to-capitalization covenant, and covenants relating to liens, asset sales and mergers, among others. The 2033 Notes also specify certain events of default, upon the occurrence of which the maturity of the notes may be accelerated, including failure to pay principal and interest, violation of covenants or default on other indebtedness, among others. The 3.29% unsecured senior notes due February 27, 2023 (the “2023 Notes”) were repaid using a combination of the proceeds from the issuance of the 2033 Notes and availability under the 2027 Revolving Credit Facility.

The Company has a $10.0 million line of credit (“Credit Line”) with Bank of America, N.A. (“Bank of America”) for short-term liquidity needs and letters of credit, with a maturity date of June 30, 2024. The Credit Line allows the Company to borrow at an interest rate agreed to by Bank of America and the Company at the time each borrowing is made or continued. The Company had no borrowings outstanding under the Credit Line as of December 31, 2023. Outstanding letters of credit under the Credit Line were $7.3 million and available borrowing capacity was $2.7 million as of December 31, 2023.

The Company also had $8.1 million and $3.3 million of short-term unsecured loans outstanding, as of December 31, 2023 and 2022, respectively, related to its Colombia operations.

As of December 31, 2023, the Company was in compliance with all covenants under its debt instruments.

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Leases

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Leases

(6) Leases

The Company currently leases various facilities and equipment under cancelable and noncancelable operating leases. The accounting for the Company’s leases may require judgments, which include determining whether a contract contains a lease, allocating the consideration between lease and non-lease components, and determining the incremental borrowing rates. Leases with an initial noncancelable term of 12 months or less are not recorded on the balance sheet and the related lease expense is recognized on a straight-line basis over the lease term. The Company has also elected to combine lease and non-lease components on all classes of leased assets, except for leased towing vessels for which the Company estimates approximately 70% of the costs relate to service costs and other non-lease components. Variable lease costs relate primarily to real estate executory costs (i.e. taxes, insurance and maintenance).

Future minimum lease payments under operating leases that have initial noncancelable lease terms in excess of one year were as follows (in thousands):

2024	$	38,943
2025		27,638
2026		24,945
2027		22,842
2028		18,318
Thereafter		79,755
Total lease payments		212,441
Less: imputed interest		(40,290	)
Operating lease liabilities	$	172,151

The following table summarizes lease costs (in thousands):

	Year Ended December 31,
	2023			2022			2021
Operating lease cost	$	42,821		$	42,319		$	40,786
Variable lease cost		2,376			1,780			1,793
Short-term lease cost		30,005			25,365			17,914
Sublease income		(3,223	)		(305	)		(1,032	)
Total lease cost	$	71,979		$	69,159		$	59,461

The following table summarizes other supplemental information about the Company’s operating leases:

	December 31,
	2023			2022			2021
Weighted average discount rate		4.4	%		4.1	%		3.8	%
Weighted average remaining lease term	9 years			9 years			9 years

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Impairments and Other Charges

12 Months Ended

Dec. 31, 2023

Asset Impairment Charges [Abstract]

Impairments and Other Charges

(7) Impairments and Other Charges

During the third quarter of 2021, the Company decided to exit the Hawaii marine transportation market, selling marine transportation equipment including four coastal tank barges, seven coastal tugboats, and certain other assets for aggregate cash proceeds of $17.2 million. In addition, as of September 30, 2021, the Company retired and classified as held for sale, an additional 12 coastal tank barges and four coastal tugboats which were underutilized. The sales and retirements of coastal marine transportation equipment resulted in an aggregate non‑cash impairment charge of $97.5 million to reduce the carrying value of these assets to their estimated sales prices, net of costs to sell.

As a result of the sale of the Hawaii marine transportation equipment, and the decision to retire certain additional underutilized coastal tank barges and tugboats, the Company concluded that a triggering event had occurred and performed interim quantitative impairment tests as of September 30, 2021 for certain of KMT’s long-lived assets and goodwill within the coastal marine market.

The Company determined the estimated fair value of such long-lived assets using a combination of a cost approach, a discounted cash flow analysis, and a market approach. The Company determined the estimated fair value of the reporting unit using a combination of a discounted cash flow analysis and a market approach for comparable companies. These analyses included management’s judgment regarding short-term and long-term internal forecasts, updated for recent events, appropriate discount rates, and capital expenditures using inputs characteristic of a Level 3 fair value measurement.

In performing the impairment test of certain long-lived assets within KMT, the Company determined that the carrying value of certain long-lived assets, including certain coastal marine transportation equipment and operating lease right-of-use assets, were no longer recoverable, resulting in a non-cash impairment charge of $24.2 million during the three months ended September 30, 2021 to reduce such long-lived assets to fair value.

Based upon the results of the goodwill impairment test, the Company concluded that the carrying value of one reporting unit in KMT exceeded its estimated fair value. The carrying value of the reporting unit, including goodwill, and after recording impairments of long-lived assets identified above, exceeded its estimated fair value, resulting in a non-cash goodwill impairment charge of $219.1 million for the three months ended September 30, 2021.

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Stock Award Plans

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Stock Award Plans

(8) Stock Award Plans

The Company has share-based compensation plans which are described below. The compensation cost that has been charged against earnings for the Company’s stock award plans and the income tax benefit recognized in the statement of earnings for stock awards were as follows (in thousands):

	Year Ended December 31,
	2023		2022		2021
Compensation cost	$	14,941	$	13,865	$	15,713
Income tax benefit	$	3,616	$	3,533	$	4,410

The Company has an employee stock award plan for selected officers and other key employees which provides for the issuance of RSUs, stock options, restricted stock awards, and performance awards. Restricted stock and RSUs generally vest ratably over five years, however, the plan includes a provision for the continued vesting of unvested stock options and RSUs for employees who meet certain

years of service and age requirements at the time of their retirement. The provision results in shorter expense accrual periods on stock options and RSUs granted to employees who are nearing retirement and meet the service and age requirements. At December 31, 2023, there were 2,045,694 shares available for future grants under the Plan.

The exercise price for each option equals the fair market value per share of the Company’s common stock on the date of grant. Substantially all stock options outstanding under the plan have terms of seven years and vest ratably over three years. No performance awards payable in stock have been awarded under the plan and no outstanding stock options under the employee plan were issued with stock appreciation rights.

The following is a summary of the stock option activity under the employee plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		396,165		$	70.06
Exercised		(117,896	)	$	60.84
Expired		(23,024	)	$	73.66
Outstanding at December 31, 2023		255,245		$	74.00

The following table summarizes information about the Company’s outstanding and exercisable stock options under the employee plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)
$64.89		15,500		1.3	$	64.89				15,500	$	64.89
$73.29 – $75.50		233,040		2.1	$	74.29				233,040	$	74.29
$84.90		6,705		2.3	$	84.90				6,705	$	84.90
$64.89 – $84.90		255,245		2.0	$	74.00	$	1,187		255,245	$	74.00	$	1,187

There were no unvested restricted stock awards under the employee plan at December 31, 2023 and 2022 and no restricted stock awards were granted under the employee plan during 2023, 2022, and 2021.

The following is a summary of RSU activity under the employee plan described above:

	Unvested RSUs			Weighted Average Grant Date Fair Value Per Unit
Nonvested balance at December 31, 2022		558,819		$	62.13
Granted		184,440		$	72.23
Vested		(161,550	)	$	64.85
Forfeited		(27,105	)	$	63.68
Nonvested balance at December 31, 2023		554,604		$	64.61

The weighted average grant date fair value of RSUs granted for the years ended December 31, 2023, 2022, and 2021 was $72.23, $66.13, and $51.36, respectively.

During February 2024, the Company granted 164,793 RSUs to selected officers and other key employees under its employee stock award plan, which substantially all vest ratably over five years.

The Company has a stock award plan for nonemployee directors of the Company which provides for the issuance of stock options and restricted stock. The director plan provides for automatic grants of restricted stock to nonemployee directors after each annual meeting of stockholders. In addition, the director plan allows for the issuance of stock options or restricted stock in lieu of cash for all or part of the annual director fee at the option of the director. The exercise prices for all options granted under the plan are equal to the fair market value per share of the Company’s common stock on the date of grant. The terms of the options are ten years. The restricted

stock issued after each annual meeting of stockholders vests six months after the date of grant. Options granted and restricted stock issued in lieu of cash director fees vest in equal quarterly increments during the year to which they relate. At December 31, 2023, 369,360 shares were available for future grants under the director plan. The director stock award plan is intended as an incentive to attract and retain qualified independent directors.

The following is a summary of the stock option activity under the director plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		56,480		$	86.19
Granted		3,865		$	72.83
Exercised		—		$	—
Expired		(30,000	)	$	80.04
Outstanding at December 31, 2023		30,345		$	90.57

The following table summarizes information about the Company’s outstanding and exercisable stock options under the director plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)
$70.65 – $73.57		7,053		6.6	$	71.85				6,278	$	71.75
$84.90 – $85.30		5,292		4.8	$	85.10				5,292	$	85.10
$99.52		18,000		0.3	$	99.52				18,000	$	99.52
$70.65 – $99.52		30,345		2.6	$	90.57	$	47		29,570	$	91.04	$	42

The following is a summary of the restricted stock award activity under the director plan described above:

	Unvested Restricted Stock Award Shares			Weighted Average Grant Date Fair Value Per Share
Nonvested balance at December 31, 2022		1,698		$	65.36
Granted		31,526		$	72.67
Vested		(32,604	)	$	72.29
Nonvested balance at December 31, 2023		620		$	72.65

The weighted average grant date fair value of restricted stock awards granted under the director plan for the years ended December 31, 2023, 2022, and 2021 were $72.67, $64.61, and $65.13, respectively.

The total intrinsic value of all stock options exercised under all of the Company’s plans was $1.5 million, $0.4 million, and $0.1 million for the years ended December 31, 2023, 2022, and 2021, respectively.

The total fair value of all the restricted stock vestings under all of the Company’s plans was $2.5 million, $3.2 million, and $5.3 million for the years ended December 31, 2023, 2022, and 2021, respectively. The actual tax benefit realized for tax deductions from restricted stock vestings was $0.6 million, $0.8 million, and $1.5 million for the years ended December 31, 2023, 2022, and 2021, respectively.

The total fair value of all the RSU vestings under the Company’s employee plan was $10.9 million, $9.5 million, and $4.4 million for the years ended December 31, 2023, 2022, and 2021, respectively. The actual tax benefit realized for tax deductions from RSU vestings was $2.6 million, $2.4 million, and $1.2 million for the years ended December 31, 2023, 2022, and 2021, respectively.

As of December 31, 2023, there was $45,000 of unrecognized compensation cost related to restricted stock and $15.3 million related to nonvested RSUs. The restricted stock is expected to be recognized over a weighted average period of approximately 0.2 years and RSUs over approximately 2.7 years.

There were no stock options granted under the employee plan during the years ended December 31, 2023, 2022, and 2021. The weighted average per share fair value of stock options granted under the director plan during the year ended December 31, 2023 was $32.33 and the fair value of the stock options was $0.1 million. There were no stock options granted under the director plan during the years ended December 31, 2022 and 2021. The Company currently uses treasury stock shares for restricted stock grants, RSU vestings, and stock option exercises. The fair value of each stock option was determined using the Black-Scholes option pricing model.

The key input variables used in valuing the stock options granted were as follows:

	Year Ended December 31,
	2023
Dividend yield	None
Average risk-free interest rate		3.7	%
Stock price volatility		35	%
Estimated option term	7 years

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Taxes on Income

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Taxes on Income

(9) Taxes on Income

Earnings (loss) before taxes on income and details of the provision (benefit) for taxes on income were as follows (in thousands):

	Year Ended December 31,
	2023			2022		2021
Earnings (loss) before taxes on income:
United States	$	293,011		$	164,590	$	(290,181	)
Foreign		1,114			385		(420	)
	$	294,125		$	164,975	$	(290,601	)
Provision (benefit) for taxes on income:
U.S. Federal:
Current	$	(41	)	$	513	$	(460	)
Deferred		61,205			34,980		(48,843	)
	$	61,164		$	35,493	$	(49,303	)
U.S. State:
Current	$	5,498		$	3,793	$	1,560
Deferred		4,093			2,802		4,424
	$	9,591		$	6,595	$	5,984
Foreign:
Current	$	465		$	126	$	(511	)
	$	465		$	126	$	(511	)
Consolidated:
Current	$	5,922		$	4,432	$	589
Deferred		65,298			37,782		(44,419	)
	$	71,220		$	42,214	$	(43,830	)

On November 13, 2021, the voters of the state of Louisiana approved a constitutional amendment that removed the corporate tax deduction for federal income taxes paid and lowered the corporate income tax rate from 8% to 7.5% effective January 1, 2022. The result of the amendment was an increase in the effective Louisiana state income tax rate, net of deduction for federal income tax, from 6.3% to 7.5%. As a result of the amendment, the Company recognized a one-time deferred tax provision of $5.7 million during the fourth quarter of 2021 due to remeasuring the Company’s Louisiana and U.S. deferred tax assets and liabilities based on the new effective Louisiana state income tax rate.

During 2021, the Company received a tax refund of $119.5 million, including accrued interest, for its 2019 tax return related to net operating losses being carried back to offset taxable income generated between 2014 and 2017.

At December 31, 2022, the Company had a federal income tax receivable of $70.4 million, included in Accounts Receivable – Other on the balance sheet. In April 2023, the Company received its tax refund of $70.4 million plus accrued interest.

The Company’s provision (benefit) for taxes on income varied from the statutory federal income tax rate due to the following:

	Year Ended December 31,
	2023			2022			2021
United States income tax statutory rate		21.0	%		21.0	%		21.0	%
State and local taxes, net of federal benefit		2.6			3.1			(1.7	)
Other – net		0.6			1.5			(4.2	)
		24.2	%		25.6	%		15.1	%

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities were as follows (in thousands):

	December 31,
	2023			2022
Deferred tax assets:
Allowance for doubtful accounts	$	1,549		$	1,556
Inventory		10,500			11,679
Insurance accruals		6,077			4,856
Deferred compensation		11,441			7,703
Unrealized gain on defined benefit plans		(9,982	)		(5,532	)
Goodwill and other intangibles		39,719			52,847
Operating loss carryforwards		52,082			79,699
Retirement benefits		3,548			5,472
Other		13,467			9,962
		128,401			168,242
Valuation allowances		(22,073	)		(19,960	)
		106,328			148,282
Deferred tax liabilities:
Property		(695,233	)		(671,830	)
Deferred state taxes		(90,457	)		(87,445	)
Other		(17,195	)		(14,891	)
		(802,885	)		(774,166	)
	$	(696,557	)	$	(625,884	)

During 2023, the Company generated federal taxable income which was completely offset by federal net operating loss carryforwards. The Company had federal operating loss deferred tax assets of $19.8 million and $47.9 million at December 31, 2023 and 2022, respectively.

The Company had state operating loss deferred tax assets of $27.2 million and $26.6 million at December 31, 2023 and 2022, respectively. The valuation allowance for state deferred tax assets as of December 31, 2023 and 2022 was $17.0 million and $14.8 million, respectively, related to the Company’s state net operating loss carryforwards based on the Company’s determination that it is more likely than not that the deferred tax assets will not be realized. Expiration of these state net operating loss carryforwards vary by state through 2030 and none will expire in fiscal 2024.

As of December 31, 2023 and 2022, the Company had a Canadian net operating loss carryforward of $5.1 million which expires between 2037 and 2043. A full valuation allowance has been provided for this asset.

The Company or one of its subsidiaries files income tax returns in the United States federal jurisdiction and various state jurisdictions. During the first quarter of 2023, the Internal Revenue Service (“IRS”) communicated to the Company that it had completed its examination of the Company’s federal income tax returns for the years 2013 through 2020. With few exceptions, the Company and its subsidiaries’ state income tax returns are open to audit under the statute of limitations for the 2017 through 2022 tax years.

As of December 31, 2023, the Company has provided a liability of $0.8 million for unrecognized tax benefits related to various income tax issues which includes interest and penalties. The amount that would impact the Company’s effective tax rate, if recognized, is $0.7 million, with the difference between the total amount of unrecognized tax benefits and the amount that would impact the effective tax rate being primarily related to the federal tax benefit of state income tax items. It is not reasonably possible to determine if the liability for unrecognized tax benefits will significantly change prior to December 31, 2024 due to the uncertainty of possible examination results.

A reconciliation of the beginning and ending amount of the liability for unrecognized tax benefits is as follows (in thousands):

	Year Ended December 31,
	2023			2022			2021
Balance at beginning of year	$	662		$	737		$	783
Additions based on tax positions related to the current year		—			13			13
Additions for tax positions of prior years		—			66			281
Reductions for tax positions of prior years		(14	)		(154	)		(340	)
Balance at end of year	$	648		$	662		$	737

The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes. The Company had $0.2 million of accrued liabilities for the payment of interest and penalties at both December 31, 2023 and 2022.

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Earnings Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Earnings Per Share

(10) Earnings Per Share

The following table presents the components of basic and diluted earnings (loss) per share (in thousands, except per share amounts):

	Year Ended December 31,
	2023			2022			2021
Net earnings (loss) attributable to Kirby	$	222,935		$	122,291		$	(246,954	)
Undistributed earnings allocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — basic		222,873			122,258			(246,954	)
Undistributed earnings allocated to restricted shares		62			33			—
Undistributed earnings reallocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — diluted	$	222,873		$	122,258		$	(246,954	)
Shares outstanding:
Weighted average common stock issued and outstanding		59,548			60,055			60,099
Weighted average unvested restricted stock		(17	)		(17	)		(46	)
Weighted average common stock outstanding — basic		59,531			60,038			60,053
Dilutive effect of stock options and restricted stock units		326			291			—
Weighted average common stock outstanding — diluted		59,857			60,329			60,053
Net earnings (loss) per share attributable to Kirby common stockholders:
Basic	$	3.74		$	2.04		$	(4.11	)
Diluted	$	3.72		$	2.03		$	(4.11	)

Diluted earnings per share was computed using the treasury stock method. Certain outstanding options to purchase approximately 33,000, 381,000, and 567,000 shares of common stock were excluded in the computation of diluted earnings per share as of December 31, 2023, 2022, and 2021, respectively, as such stock options would have been antidilutive. Certain outstanding RSUs to convert to 7,000 shares of common stock were also excluded in the computation of diluted earnings per share as of December 31, 2021 as such RSUs would have been antidilutive. No RSUs were antidilutive at December 31, 2023 and 2022.

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Inventories

12 Months Ended

Dec. 31, 2023

Inventory Disclosure [Abstract]

Inventories

(11) Inventories

The following table presents the details of inventories — net (in thousands):

	December 31,
	2023		2022
Finished goods	$	351,050	$	358,702
Work in process		103,339		103,146
	$	454,389	$	461,848

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Retirement Plans

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

Retirement Plans

(12) Retirement Plans

The Company sponsors a defined benefit plan (the “Kirby Pension Plan”) for its inland vessel personnel and shore based tankermen. The plan benefits are based on an employee’s years of service and compensation. The plan assets consist primarily of equity and fixed income securities.

On April 12, 2017, the Company amended the Kirby Pension Plan to cease all benefit accruals for periods after May 31, 2017 for certain participants. Participants grandfathered and not impacted were those, as of the close of business on May 31, 2017, who either (a) had completed 15 years of pension service or (b) had attained age 50 and completed 10 years of pension service. Participants non-grandfathered are eligible to receive discretionary 401(k) plan contributions.

On February 14, 2018, with the acquisition of Higman Marine, Inc. (“Higman”), the Company assumed Higman’s pension plan (the “Higman Pension Plan”) for its inland vessel personnel and office staff. On March 27, 2018, the Company amended the Higman Pension Plan to close it to all new entrants and cease all benefit accruals for periods after May 15, 2018 for all participants. The Company made contributions to the Higman Pension Plan of $8.2 million, $0.9 million and $0.5 million for the years ended December 31, 2023, 2022 and 2021, respectively.

The aggregate fair value of plan assets of the Company’s pension plans was $375.9 million and $341.1 million at December 31, 2023 and 2022, respectively. Pension assets were allocated among asset categories as follows:

	December 31,						Current Minimum, Target and Maximum
Asset Category	2023			2022			Allocation Policy
U.S. equity securities		51	%		50	%		45	%	— 50%	— 55%
International equity securities		20			20			12	%	— 20%	— 28%
Debt securities		29			30			20	%	— 30%	— 40%
Cash and cash equivalents		—			—			0	%	— 0%	— 0%
		100	%		100	%

At December 31, 2022, $4.8 million was held in cash as well as debt and equity securities classified within Level 1 of the valuation hierarchy. There were no investments within Level 3 of the valuation hierarchy at December 31, 2023 and 2022. All other plan assets are invested in common collective trusts and valued using the net asset value per share practical expedient and therefore not valued within the valuation hierarchy.

The Company’s investment strategy focuses on total return on invested assets (capital appreciation plus dividend and interest income). The primary objective in the investment management of assets is to achieve long-term growth of principal while avoiding excessive risk. Risk is managed through diversification of investments within and among asset classes, as well as by investing in asset classes offering sufficient liquidity and trading history.

The Company makes various assumptions when determining defined benefit plan costs including, but not limited to, the current discount rate and the expected long-term return on plan assets. Discount rates are determined annually and are based on a yield curve that consists of a hypothetical portfolio of high quality corporate bonds with maturities matching the projected benefit cash flows. The Company assumed that plan assets would generate a long-term rate of return of 6.75% in both 2023 and 2022. The Company developed its expected long-term rate of return assumption by evaluating input from investment consultants comparing historical returns for various asset classes with its actual and targeted plan investments. The Company believes that its long-term asset allocation, on average, will approximate the targeted allocation.

The Company’s pension plan funding strategy is to make annual contributions in amounts equal to or greater than amounts necessary to meet minimum government funding requirements. The plan’s benefit obligations are based on a variety of demographic and economic assumptions, and the pension plan assets’ returns are subject to various risks, including market and interest rate risk, making an accurate prediction of the pension plan contribution difficult. The Company’s pension plan funding was 115% of the pension plans’ accumulated benefit obligation at December 31, 2023, including both the Kirby Pension Plan and the Higman Pension Plan.

The Company sponsors an unfunded defined benefit health care plan that provides limited postretirement medical benefits to employees who met minimum age and service requirements, and to eligible dependents. The plan limits cost increases in the Company’s contribution to 4% per year. The plan is contributory, with retiree contributions adjusted annually. The plan eliminated coverage for future retirees as of December 31, 2011. The Company also has an unfunded defined benefit supplemental executive retirement plan (“SERP”) that was assumed in an acquisition in 1999. That plan ceased to accrue additional benefits effective January 1, 2000.

The following table presents the change in benefit obligation and plan assets for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits												Other Postretirement Benefits
	Pension Plans						SERP						Postretirement Welfare Plan
	2023			2022			2023			2022			2023			2022
Change in benefit obligation
Benefit obligation at beginning of year	$	339,509		$	495,272		$	833		$	1,033		$	432		$	582
Service cost		3,695			6,538			—			—			—			—
Interest cost		18,356			14,779			43			29			22			17
Actuarial (gain) loss		13,241			(158,816	)		91			(74	)		65			(58	)
Gross benefits paid		(32,052	)		(12,665	)		(153	)		(155	)		(104	)		(109	)
Settlements		—			(5,599	)		—			—			—			—
Benefit obligation at end of year	$	342,749		$	339,509		$	814		$	833		$	415		$	432
Accumulated benefit obligation at end of year	$	326,987		$	325,274		$	814		$	833		$	415		$	432
Weighted-average assumption used to determine benefit obligation at end of year
Discount rate (a)	5.1%/5.2%				5.5	%		5.1	%		5.5	%		5.1	%		5.5	%
Rate of compensation increase	Service-based table			Service-based table				—			—			—			—
Health care cost trend rate
Initial rate		—			—			—			—			6.25	%		6.50	%
Ultimate rate		—			—			—			—			5.0	%		5.0	%
Years to ultimate		—			—			—			—		2029			2029
Change in plan assets
Fair value of plan assets at beginning of year	$	341,061		$	430,821		$	—		$	—		$	—		$	—
Actual return on plan assets		58,734			(72,402	)		—			—			—			—
Employer contribution		8,174			906			153			155			104			109
Gross benefits paid		(32,052	)		(12,665	)		(153	)		(155	)		(104	)		(109	)
Settlements		—			(5,599	)		—			—			—			—
Fair value of plan assets at end of year	$	375,917		$	341,061		$	—		$	—		$	—		$	—

(a)The 2023 discount rate was 5.1% for the Kirby Pension Plan and 5.2% for the Higman Pension Plan. The 2022 discount rate was 5.5% for both the Kirby Pension Plan and the Higman Pension Plan.

During the year ending December 31, 2023, actual returns on plan assets performed better than expected which improved the funding position.

During the year ending December 31, 2022, actual returns on plan assets performed less than expected which deteriorated the funding position but the overall funded position at December 31, 2022 was improved due to a decrease in the benefit obligation primarily due to an increase in the discount rate.

The following table presents the funded status and amounts recognized in the Company’s consolidated balance sheet for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits												Other Postretirement Benefits
	Pension Plans						SERP						Postretirement Welfare Plan
	2023			2022			2023			2022			2023			2022
Funded status at end of year
Fair value of plan assets	$	375,917		$	341,061		$	—		$	—		$	—		$	—
Benefit obligations		(342,749	)		(339,509	)		(814	)		(833	)		(415	)		(432	)
Funded status and amount recognized at end of year	$	33,168		$	1,552		$	(814	)	$	(833	)	$	(415	)	$	(432	)
Amounts recognized in the consolidated balance sheets
Noncurrent asset		42,698			18,695			—			—			—			—
Current liability		—			—			(106	)		(106	)		(46	)		(49	)
Long-term liability		(9,530	)		(17,143	)		(708	)		(727	)		(369	)		(383	)
Amounts recognized in accumulated other comprehensive income
Net actuarial (gain) loss	$	(48,033	)	$	(25,449	)	$	391		$	324		$	(1,890	)	$	(2,299	)
Prior service cost (credit)		—			—			—			—			—			—
Accumulated other compensation income	$	(48,033	)	$	(25,449	)	$	391		$	324		$	(1,890	)	$	(2,299	)

The following table presents the expected cash flows for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits								Other Postretirement Benefits
	Pension Plans				SERP				Postretirement Welfare Plan
	2023		2022		2023		2022		2023		2022
Expected employer contributions
First year	$	1,770	$	8,374	$	—	$	—	$	—	$	—
Expected benefit payments (gross)
Year one	$	16,696	$	16,312	$	108	$	108	$	47	$	50
Year two		17,513		16,899		103		104		46		49
Year three		18,169		17,808		98		99		44		47
Year four		19,096		18,650		93		94		43		45
Year five		19,860		19,707		88		90		41		43
Next five years		108,717		110,417		337		359		167		176

The components of net periodic benefit cost and other changes in plan assets and benefit obligations recognized in other comprehensive income for the Company’s defined benefit plans were as follows (in thousands):

	Pension Benefits
	Pension Plans									SERP
	2023			2022			2021			2023			2022			2021
Components of net periodic benefit cost
Service cost	$	3,695		$	6,538		$	7,961		$	—		$	—		$	—
Interest cost		18,356			14,779			14,239			43			29			31
Expected return on plan assets		(22,910	)		(28,399	)		(26,244	)		—			—			—
Amortization of actuarial loss		—			34			4,193			23			30			40
Net periodic benefit cost		(859	)		(7,048	)		149			66			59			71
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Current year actuarial (gain) loss		(22,583	)		(58,015	)		(44,583	)		91			(74	)		(12	)
Recognition of actuarial loss		—			(34	)		(4,193	)		(23	)		(30	)		(40	)
Total recognized in other comprehensive income		(22,583	)		(58,049	)		(48,776	)		68			(104	)		(52	)
Total recognized in net periodic benefit cost and other comprehensive income	$	(23,442	)	$	(65,097	)	$	(48,627	)	$	134		$	(45	)	$	19
Weighted average assumptions used to determine net periodic benefit cost
Discount rate (a)		5.5	%	3.0% / 3.1%			2.8% / 2.9%				5.5	%		3.0	%		2.8	%
Expected long-term rate of return on plan assets		6.75	%		6.75	%		6.75	%		—			—			—
Rate of compensation increase	Service-based table			Service-based table			Service-based table				—			—			—

(a)The 2023 discount rate for benefit cost is 5.5% for both the Kirby Pension Plan and the Higman Pension Plan. The 2022 discount rate for benefit cost is 3.0% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan.

The components of net periodic benefit cost and other changes in benefit obligations recognized in other comprehensive income for the Company’s postretirement benefit plan were as follows (in thousands):

	Other Postretirement Benefits
	Postretirement Welfare Plan
	2023			2022			2021
Components of net periodic benefit cost
Interest cost	$	22		$	17		$	17
Amortization of actuarial gain		(344	)		(394	)		(451	)
Net periodic benefit cost		(322	)		(377	)		(434	)
Other changes in benefit obligations recognized in other comprehensive income
Current year actuarial loss (gain)		65			(58	)		104
Recognition of actuarial gain		344			394			451
Total recognized in other comprehensive income		409			336			555
Total recognized in net periodic benefit cost and other    comprehensive income	$	87		$	(41	)	$	121
Weighted average assumptions used to determine net periodic benefit cost
Discount rate		5.5	%		3.0	%		2.8	%
Health care cost trend rate:
Initial rate		6.50	%		6.25	%		6.50	%
Ultimate rate		5.0	%		5.0	%		5.0	%
Years to ultimate	2029			2027			2025

The Company also contributes to a multiemployer pension plan pursuant to a collective bargaining agreement which covers certain vessel crew members of its coastal operations and expires on April 30, 2025. The Company began participation in the Seafarers Pension Trust (“SPT”) with the Penn Maritime, Inc. acquisition on December 14, 2012.

Contributions to the SPT are made currently based on a per day worked basis and charged to expense as incurred and included in costs of sales and operating expenses in the consolidated statement of earnings. During 2023 and 2022, the Company made contributions of $0.4 million and $0.5 million, respectively, to the SPT. The Company’s contributions to the SPT did not exceed 5% of total contributions to the SPT in 2022. Total contributions for 2023 are not yet available. The Company did not pay any material surcharges in 2023 and 2022.

The federal identification number of the SPT is 13-6100329 and the Certified Zone Status is Green at December 31, 2022. The Company’s future minimum contribution requirements under the SPT are unavailable because actuarial reports for the 2023 plan year are not yet complete and such contributions are subject to negotiations between the employers and the unions. The SPT was not in endangered or critical status for the 2022 plan year, the latest period for which a report is available, as the funded status was in excess of 100%. Based on the most recent communication from the SPT, there would be no withdrawal liability if the Company chose to withdraw from the SPT although the Company currently has no intention of terminating its participation in the SPT.

The Company also contributes to a multiemployer pension plan pursuant to a collective bargaining agreement which covers certain employees of KDS in New Jersey and expires on October 8, 2028. The Company began participation in the Central Pension Fund of the International Union of Operating Engineers and Participating Employers (“CPF”) with the Stewart & Stevenson LLC acquisition on September 13, 2017.

Contributions to the CPF are made currently based on a fixed hourly rate for each hour worked or paid basis (in some cases contributions are made as a percentage of gross pay) and charged to expense as incurred and included in costs of sales and operating expenses in the consolidated statement of earnings. During 2023 and 2022, the Company made contributions of $0.6 and $0.7 million, respectively, to the CPF. Total contributions for the 2023 plan year are not yet available. The Company did not pay any material surcharges in 2023 and 2022.

The federal identification number of the CPF is 36-6052390 and the Certified Zone Status is Green at January 31, 2024. The Company’s future minimum contribution requirements under the CPF are unavailable because actuarial reports for the 2023 plan year, which ended January 31, 2024, are not yet complete and such contributions are subject to negotiations between the employers and the unions. The CPF was not in endangered or critical status for the 2022 plan year, ending January 31, 2023, the latest period for which a report is available, as the funded status was 107%. There would be no withdrawal liability if the Company chose to withdraw from the CPF although the Company currently has no intention of terminating its participation in the CPF.

In addition to the defined benefit plans, the Company sponsors various defined contribution plans for substantially all employees. The aggregate contributions to the plans were $26.9 million, $27.9 million, and $25.9 million in 2023, 2022, and 2021, respectively.

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Other Comprehensive Income (Loss)

12 Months Ended

Dec. 31, 2023

Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]

Other Comprehensive Income (Loss)

(13) Other Comprehensive Income (Loss)

The Company’s changes in other comprehensive income (loss) were as follows (in thousands):

	Year Ended December 31,
	2023									2022									2021
	Gross Amount			Income Tax (Provision) Benefit			Net Amount			Gross Amount			Income Tax (Provision) Benefit			Net Amount			Gross Amount			Income Tax Provision			Net Amount
Pension and postretirement benefits (a):
Amortization of net actuarial (gain) loss	$	(321	)	$	78		$	(243	)	$	(330	)	$	81		$	(249	)	$	3,782		$	(952	)	$	2,830
Actuarial gain		22,438			(5,467	)		16,971			58,147			(14,030	)		44,117			44,491			(10,774	)		33,717
Foreign currency translation adjustments		1,425			—			1,425			(1,049	)		—			(1,049	)		(1,061	)		—			(1,061	)
Total	$	23,542		$	(5,389	)	$	18,153		$	56,768		$	(13,949	)	$	42,819		$	47,212		$	(11,726	)	$	35,486

(a)Actuarial gains (losses) are amortized into other income (expense). (See Note 12 – Retirement Plans)

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Contingencies and Commitments

12 Months Ended

Dec. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Contingencies and Commitments

(14) Contingencies and Commitments

In 2009, the Company was named by the Environmental Protection Agency (the “EPA”) as a Potentially Responsible Party (“PRP”) in addition to a group of approximately 250 named PRPs under the Comprehensive Environmental Response, Compensation and Liability Act of 1981 (“CERCLA”) with respect to a Superfund site, the Portland Harbor Superfund site (“Portland Harbor”) in Portland, Oregon. The site was declared a Superfund site in December 2000 as a result of historical heavily industrialized use due to manufacturing, shipbuilding, petroleum storage and distribution, metals salvaging, and electrical power generation activities which led to contamination of Portland Harbor, an urban and industrial reach of the lower Willamette River located immediately downstream of downtown Portland. The Company’s involvement arises from four spills at the site after it was declared a Superfund site, as a result of predecessor entities’ actions in the area. To date, there is no information suggesting the extent of the costs or damages to be claimed from the 250 notified PRPs. Based on the nature of the involvement at the Portland Harbor site, the Company believes its potential contribution is de minimis; however, to date neither the EPA nor the named PRPs have performed an allocation of potential liability in connection with the site nor have they provided costs and expenses in connection with the site.

On February 20, 2015, the Company was served as a defendant in a Complaint originally filed on August 14, 2014, in the U.S. District Court of the Southern District of Texas - Houston Division, USOR Site PRP Group vs. A&M Contractors, USES, Inc. et al. This is a civil action pursuant to the provisions of CERCLA and the Texas Solid Waste Disposal Act for recovery of past and future response costs incurred and to be incurred by the USOR Site PRP Group for response activities at the U.S. Oil Recovery Superfund Site. The property was a former sewage treatment plant owned by defendant City of Pasadena, Texas from approximately 1945 until it was acquired by U.S. Oil Recovery in January 2009. Throughout its operating life, the U.S. Oil Recovery facility portion of the USOR Site received and performed wastewater pretreatment of municipal and Industrial Class I and Class II wastewater, characteristically hazardous waste, used oil and oily sludges, and municipal solid waste. Associated operations were conducted at the MCC Recycling facility portion of the USOR Site after it was acquired by U.S. Oil Recovery from the City of Pasadena in January 2009. The EPA and the PRP Group entered into an Administrative Settlement Agreement and Order for Remedial Investigation Study (“Study”) in May 2015. The Study has not been completed by EPA to date. The Company joined as a member of the PRP Group companies at its pro-rata allocated share.

On October 13, 2016, the Company, as a successor to Hollywood Marine, Inc. (“Hollywood Marine”), was issued a General Notice under CERCLA by the EPA in which it was named as a PRP for liabilities associated with the SBA Shipyard Site located near Jennings, Louisiana (the “Site”). The Site was added to the EPA’s National Priorities List of sites under CERCLA in September 2016. SBA used the facility for construction, repair, retrofitting, sandblasting, and cleaning and painting of barges beginning in 1965. Three barge slips and a dry dock are located off the Mermentau River. The slips were used to dock barges during cleaning or repair. In 2001, a group of PRPs that had been former customers of the SBA Shipyard facility formed an organization called the SSIC Remediation, LLC (hereinafter, “the PRP Group Companies”) to address removal actions at the Site. In 2002, EPA approved an Interim Measures/Removal Action of Hazardous/Principal Threat Wastes at SBA Shipyards, Inc. (pursuant to RCRA Section 3008(h)) that was proposed by SBA Shipyard and the PRP Group Companies. Interim removal activities were conducted from March 2001 through January 2005 under an EPA 2002 Order and Agreement. In September 2012, the Louisiana Department of Environmental Quality requested EPA address the Site under CERCLA authority. The Company, as a successor to Hollywood Marine, joined the PRP Group Companies. The PRP Group Companies have submitted a draft Study work plan to EPA for their review and comment. Higman was named as a PRP in connection with its activities at the Site. Higman is not a participant in the PRP Group Companies.

With respect to the above sites, the Company has accrued a liability, if applicable, for its estimated potential liability for its portion of the EPA’s past costs claim based on information developed to date including various factors such as the Company’s liability in proportion to other PRPs and the extent to which such costs are recoverable from third parties.

On October 13, 2016, the tug Nathan E. Stewart and barge DBL 55, an ATB owned and operated by Kirby Offshore Marine, LLC, a wholly owned subsidiary of the Company, ran aground at the entrance to Seaforth Channel on Atholone Island, British Columbia. The grounding resulted in a breach of a portion of the Nathan E. Stewart’s fuel tanks causing a discharge of diesel fuel into the water. The USCG and the NTSB designated the Company as a party of interest in their investigation as to the cause of the incident. The Canadian authorities including Transport Canada and the Canadian Transportation Safety Board investigated the cause of the incident. On October 10, 2018, the Heiltsuk First Nation filed a civil action in the British Columbia Supreme Court against a subsidiary of the Company, the master and pilot of the tug, the vessels and the Canadian government seeking unquantified damages as a result of the incident. On May 1, 2019, the Company filed a limitation action in the Federal Court of Canada seeking limitation of liability relating to the incident as provided under admiralty law. The Heiltsuk First Nation’s civil claim has been consolidated into the Federal Court limitation action as of July 26, 2019 and it is expected that the Federal Court of Canada will decide all claims against the Company. The Company is unable to estimate the potential exposure in the civil proceeding. The Company has various insurance policies covering liabilities including pollution, property, marine and general liability and believes that it has satisfactory insurance coverage for the cost of cleanup and salvage operations as well as other potential liabilities arising from the incident. The Company believes its accrual of such estimated liability is adequate for the incident and does not expect the incident to have a material adverse effect on its business or financial condition.

In addition, the Company is involved in various legal and other proceedings which are incidental to the conduct of its business, none of which in the opinion of management will have a material effect on the Company’s financial condition, results of operations or cash flows. Management believes its accrual of such estimated liability is adequate and believes that it has adequate insurance coverage or has meritorious defenses for these other claims and contingencies.

Certain Significant Risks and Uncertainties. The preparation of financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. However, in the opinion of management, the amounts would be immaterial.

The Company has issued guaranties or obtained standby letters of credit and performance bonds supporting performance by the Company and its subsidiaries of contractual or contingent legal obligations of the Company and its subsidiaries incurred in the ordinary course of business. The aggregate notional value of these instruments is $26.7 million at December 31, 2023, including $12.1 million in letters of credit and $14.6 million in performance bonds. All of these instruments have an expiration date within two years. The Company does not believe demand for payment under these instruments is likely and expects no material cash outlays to occur in connection with these instruments.

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Related Party Transactions

12 Months Ended

Dec. 31, 2023

Related Party Transactions [Abstract]

Related Party Transactions Disclosure [Text Block]

(15) Related Party Transactions

David W. Grzebinski, President and Chief Executive Officer of the Company, is a member of the board of directors for ABS, a not-for-profit that provides global classification services to the marine, offshore and gas industries. The Company paid ABS $1.5 million in 2023, $1.3 million in 2022, and $1.6 million in 2021 to perform audits and surveys of the Company’s vessels in the ordinary course of business.

Mr. Grzebinski is a member of the board of directors of UK Protection & Indemnity Association (“UK P&I”), a mutual marine protection and indemnity organization that provides protection and indemnity insurance for third party liabilities and expenses arising from vessel operations. The Company’s marine fleet is insured on a pro rata share basis through UK P&I and Standard Mutual. The Company paid $3.6 million during 2023 in premiums for coverage in the 2023-2024 policy period, $3.4 million during 2022 in premiums for coverage in the 2022-2023 policy period, and $3.2 million in 2021 in premiums for coverage in the 2021-2022 policy period in the ordinary course of business.

Amy D. Husted, Vice President, General Counsel and Secretary of the Company, is a member of the board of directors of Signal Mutual Indemnity Association Ltd (“Signal”), a group self-insurance not-for-profit organization authorized by the U.S. Department of Labor as a longshore worker’s compensation insurance provider. The Company has been a member of Signal since it was established in 1986. The Company paid Signal $0.7 million in 2023, $0.5 million in 2022 and $0.6 million in 2021 in the ordinary course of business.

The husband of Ms. Husted is a partner in the law firm of Clark Hill PLC. The Company paid the law firm $0.9 million in 2023, $1.0 million in 2022, and $2.9 million in 2021 for legal services in connection with matters in the ordinary course of business.

The brother of Christian G. O’Neil, President of Kirby Inland Marine, LP, Kirby Offshore Marine, LLC, San Jac Marine, LLC and Kirby Offshore Wind, LLC, is a partner in the law firm of W. Sean O’Neil Attorney at Law. The Company paid the law firm $0.1 million in 2023, $0.1 million in 2022, and $0.1 million in 2021 for legal services in the ordinary course of business.

Rocky B. Dewbre, a director of the Company, serves as President and Chief Operating Officer of Mansfield Service Partners. Mansfield Service Partners is under the same common control as O’Rourke Marine Services (“O’Rourke”), a distributor of lubricants, fuels, and environmental services. The Company paid O’Rourke $29.4 million in 2023 in the ordinary course of business.

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Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Principles of Consolidation

Principles of Consolidation. The consolidated financial statements include the accounts of Kirby Corporation and all majority-owned subsidiaries (the “Company”). All investments in which the Company owns 20% to 50% and exercises significant influence over operating and financial policies are accounted for using the equity method. All material intercompany accounts and transactions have been eliminated in consolidation. Certain reclassifications have been made to reflect the current presentation of financial information. Such reclassifications have no impact on previously reported net earnings (loss), stockholders’ equity, or cash flows.

Cash Equivalents

Cash Equivalents. Cash equivalents consist of all short-term, highly liquid investments with maturities of three months or less at date of purchase.

Accounts Receivable

Accounts Receivable. In the normal course of business, the Company extends credit to its customers. The Company regularly reviews the accounts and makes adequate provisions for probable uncollectible balances. It is the Company’s opinion that the accounts have no impairment, other than that for which provisions have been made. Included in accounts receivable-trade as of December 31, 2023 and 2022 were $136.3 million and $139.5 million, respectively, of accruals for revenues earned which have not been invoiced as of the end of each year.Included in accounts receivable-other as of December 31, 2023 and 2022 were $29.6 million and $27.7 million, respectively, of receivables from insurance companies to cover claims in excess of the Company’s deductible.

Accrued Insurance

Accrued Insurance. The Company’s marine transportation and distribution and services operations are subject to hazards associated with such businesses. The marine transportation business in particular is subject to property damage and casualty risks associated with operating vessels carrying large volumes of bulk liquid and dry cargo in a marine environment. The Company maintains insurance coverage against these hazards with insurance companies subject to a deductible, below which the Company is liable. The Company uses historic experience and actuarial analysis by outside consultants to estimate an appropriate level of accrued insurance liabilities including estimates on individual claims outstanding and an estimated amount for losses that may have occurred but have not been reported to the Company (“IBNR”) or not yet fully developed. If the actual number of claims and magnitude were substantially greater than assumed, the required level of accrued liabilities for claims incurred but not reported or fully developed could be materially understated. Insurance premiums, IBNR losses and incurred claim losses, up to the Company’s deductible for the years ended December 31, 2023, 2022, and 2021, were $52.5 million, $39.1 million, and $37.8 million, respectively.

Concentrations of Credit Risk

Concentrations of Credit Risk. Financial instruments which potentially subject the Company to concentrations of credit risk are primarily trade accounts receivables. The Company’s marine transportation customers include the major oil refining and petrochemical companies. The distribution and services customers are oilfield service companies, oil and gas operators and producers, on-highway transportation companies, marine transportation companies, commercial fishing companies, construction companies, power generation companies, and the United States government. The Company regularly reviews its accounts and estimates the amount of uncollectible receivables each period and establishes an allowance for uncollectible amounts. The amount of the allowance is based on the age of unpaid amounts, information about the current financial strength of customers, and other relevant information. Estimates of uncollectible amounts are revised each period, and changes are recorded in the period they become known.

Historically, credit risk with respect to these trade receivables has generally been considered minimal because of the financial strength of the Company’s customers; however, a United States or global recession or other adverse economic condition could impact the collectability of certain customers’ trade receivables which could have a material effect on the Company’s results of operations.

Inventories

Inventories. Inventories are stated at the lower of average cost or net realizable value.

Property, Maintenance and Repairs

Property, Maintenance and Repairs. Property is recorded at cost or acquisition date fair value; improvements and betterments are capitalized as incurred. Depreciation is recorded using the straight-line method over the estimated useful lives of the individual assets as follows: marine transportation equipment, 5-40 years; buildings, 10-40 years; other equipment, 2-10 years; and leasehold improvements, term of lease. When property items are retired, sold, or otherwise disposed of, the related cost and accumulated depreciation are removed from the accounts with any gain or loss on the disposition included in the statement of earnings. Maintenance and repairs on vessels built for use on the inland waterways are charged to operating expense as incurred and includes the costs incurred

in United States Coast Guard (“USCG”) inspections unless the shipyard extends the life, improves the operating capacity, or replaces significant components of the vessel, which results in the costs being capitalized.

The following table summarizes the balances of property and equipment – net (in thousands):

	December 31,
	2023			2022
Land	$	39,567		$	38,551
Marine transportation equipment		5,029,653			4,837,379
Buildings and other equipment		641,871			505,942
Construction in progress		112,947			70,271
	$	5,824,038		$	5,452,143
Accumulated depreciation		(1,962,933	)		(1,818,681	)
Property and equipment – net	$	3,861,105		$	3,633,462

Drydocking on Ocean-Going Vessels

Drydocking on Ocean-Going Vessels. The Company’s ocean-going vessels are subject to regulatory drydocking requirements after certain periods of time to be inspected, have planned major maintenance performed and be recertified by the American Bureau of Shipping (“ABS”). These recertifications generally occur twice in a five-year period. The Company defers the drydocking expenditures incurred on its ocean-going vessels due to regulatory marine inspections by the ABS and amortizes the costs of the shipyard over the period between drydockings, generally 30 or 60 months, depending on the type of major maintenance performed. Drydocking expenditures that extend the life, improve the operating capability, or replace significant components of the vessel are capitalized. The Company recognized amortization of major maintenance costs of $29.0 million, $29.0 million, and $33.2 million for the years ended December 31, 2023, 2022, and 2021, respectively, in costs of sales and operating expenses. Routine repairs and maintenance on ocean-going vessels are expensed as incurred. Interest is capitalized on the construction of new ocean-going vessels. For the years ended December 31, 2023, 2022 and 2021, no interest was capitalized.

Environmental Liabilities

Environmental Liabilities. The Company expenses costs related to environmental events as they are incurred or when a loss is considered probable and reasonably estimable.

Goodwill

Goodwill. The excess of the purchase price over the fair value of identifiable net assets acquired in transactions accounted for as a purchase is included in goodwill. The Company conducted its annual goodwill impairment tests at November 30, 2023, 2022, and 2021. The Company also conducted an interim goodwill impairment test at September 30, 2021. Refer to Note 7, Impairments and other charges for more information. The Company will continue to conduct goodwill impairment tests as of November 30 of subsequent years, or whenever events or circumstances indicate that interim impairment testing is necessary. The amount of goodwill impairment, if any, is typically measured based on a combination of projected discounted future operating cash flows using an appropriate discount rate and a market approach for comparable companies. The following table summarizes the changes in goodwill (in thousands):

	Marine Transportation			Distribution and Services			Total
Balance at December 31, 2022 (gross)		505,784			560,155			1,065,939
Accumulated impairment and amortization		(237,626	)		(389,565	)		(627,191	)
Balance at December 31, 2022 and 2023	$	268,158		$	170,590		$	438,748

Other Intangibles

Other Intangibles. Other intangibles include assets for favorable contracts and customer relationships, distributorship and dealership agreements, trade names and non-compete agreements and liabilities for unfavorable leases and contracts. The following table summarizes the balances of other intangible assets and other intangible liabilities (in thousands):

	December 31,
	2023			2022
Other intangible assets – gross	$	184,622		$	203,242
Accumulated amortization		(141,695	)		(151,779	)
Other intangible assets – net	$	42,927		$	51,463
Other intangible liabilities – gross	$	8,800		$	13,860
Accumulated amortization		(8,800	)		(13,280	)
Other intangible liabilities – net	$	—		$	580

The costs of intangible assets and liabilities are amortized to expense in a systematic and rational manner over their estimated useful lives. For the years ended December 31, 2023, 2022, and 2021, the amortization expense for intangibles was $8.1 million, $7.6 million, and $7.8 million, respectively. Estimated net amortization expense for amortizable intangible assets and liabilities for the next five years

(2024 – 2028) is approximately $8.5 million, $8.5 million, $6.3 million, $5.0 million, and $3.5 million, respectively, and $11.1 million thereafter. As of December 31, 2023, the weighted average amortization period for intangible assets and liabilities was approximately seven years.

Revenue Recognition

Revenue Recognition. The majority of marine transportation revenue is derived from term contracts, ranging from one to three years, some of which have renewal options, and the remainder is from spot contracts. The majority of the term contracts by revenue are for terms of one year. The Company provides marine transportation services for its customers and, in almost all cases, does not assume ownership of the products it transports. The Company enters into agreements with its customers to transport cargo from a designated origin to a designated destination at a set rate (affreightment) or at a daily rate (time charter). The rate may or may not escalate during the term of the contract, however, the base rate generally remains constant and contracts often include escalation provisions to recover changes in specific costs such as fuel. Time charter or contracts of affreightment of one year or greater are considered term contract revenues and agreements of less than a year are included in spot contract revenues. Spot contracts typically involve an agreement with a customer to move cargo from a specific origin to a designated destination for a rate generally negotiated at the time the cargo movement takes place. Spot contract rates are typically at the current “market” rate, including fuel, and are subject to market volatility. The Company uses a voyage accounting method of revenue recognition for its marine transportation revenues which allocates voyage revenue based on the percent of the voyage completed during the period. The performance of the service is invoiced as the transaction occurs and payment is required depending on each specific customer’s credit.

Distribution products and services are generally sold based upon purchase orders or preferential service agreements with the customer that include fixed or determinable prices. Parts sales are recognized when control transfers to the customer, generally when title passes upon shipment to customers. Service revenue is recognized over time as the service is provided using measures of progress utilizing hours worked or costs incurred as a percentage of estimated hours or expected costs. Revenue from rental agreements is generally recognized on a straight-line basis over the rental period. The Company recognizes the revenues on manufacturing activities upon shipment and transfer of control to the customer. The transactions in the distribution and services segment (“KDS”) are typically invoiced as parts are shipped or upon the completion of the service job. Contract manufacturing activities are generally invoiced upon shipment and the Company will often get deposits from its customers prior to starting work, or progress payments during the project depending on the credit worthiness of the customer and the size of the project.

Stock-Based Compensation

Stock-Based Compensation. The Company has share-based compensation plans covering selected officers and other key employees as well as the Company’s Board of Directors. Stock-based grants made under the Company’s stock plans are measured at fair value on the date of the grant and the cost for all grants made under the director plan and for grants made under the employee plan is generally recognized ratably over the vesting period of the restricted stock unit (“RSU”), stock option, or restricted stock. The employee plan, however, includes a provision for the continued vesting of unvested stock options and RSUs for employees who meet certain years of service and age requirements at the time of their retirement. The provision results in shorter expense accrual periods on stock options and RSUs granted to employees who are nearing retirement and meet the service and age requirements. Stock option grants are valued at the date of grant as calculated under the Black-Scholes option pricing model. The Company accounts for forfeitures as they occur. The Company’s stock-based compensation plans are more fully described in Note 8, Stock Award Plans.

Taxes on Income

Taxes on Income. The Company follows the asset and liability method of accounting for income taxes. Under the asset and liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

Treasury Stock

Treasury Stock. The Company follows the average cost method of accounting for treasury stock transactions.

Impairment of Long-Lived Assets and for Long-Lived Assets to Be Disposed Of

Impairment of Long-lived Assets and for Long-lived Assets to Be Disposed Of. The Company performs an impairment assessment whenever events or changes in circumstances indicate that the carrying amount of long-lived assets may not be recoverable.

Recoverability on marine transportation assets is assessed based on vessel classes, not on individual assets, because identifiable cash flows for individual marine transportation assets are not available. Projecting customer contract volumes allows estimation of future cash flows by projecting pricing and utilization by vessel class but it is not practical to project which individual marine transportation asset will be utilized for any given contract. Because customers generally do not specify which particular vessel is used, prices are quoted based on vessel classes not individual assets. Nominations of vessels for specific jobs are determined on a day by day basis and are a function of the equipment class required and the geographic position of vessels within that class at that particular time as vessels within a class are interchangeable and provide the same service. The Company’s vessels are mobile assets and equipped to operate in geographic regions throughout the United States and the Company has in the past and expects to continue to move vessels from one region to another when it is necessary due to changing markets and it is economical to do so. Barge vessel classes are based on similar capacities, hull type, and type of product and towing vessels are based on similar hull type and horsepower.

If a triggering event is identified, the Company compares the carrying amount of the asset group to the estimated undiscounted future cash flows expected to result from the use of the asset group. If the carrying amount of the asset group exceeds the estimated undiscounted future cash flows, the Company measures the amount of the impairment by comparing the carrying amount of the asset group to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell.

Fair Value Measurements

Fair Value Measurements. The accounting guidance for using fair value to measure certain assets and liabilities establishes a three tier value hierarchy, which prioritizes the inputs to valuation techniques used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little, if any, market data exists, therefore requiring an entity to develop its own assumptions about the assumptions that market participants would use in pricing the asset or liability. The fair value of the Company’s debt instruments is described in Note 5, Long-Term Debt.

Accounting Standards Adoptions

Accounting Standards

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”) which requires entities to disclose additional information in specified categories with respect to the reconciliation of the effective tax rate to the statutory rate for federal, state, and foreign income taxes. ASU 2023-09 is effective for annual and interim periods beginning after December 15, 2023, with early adoption permitted. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements.

In November 2023, the FASB issued ASU No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”) to improve reportable segment disclosure requirements. The amendments require disclosure of significant segment expenses regularly provided to the chief operating decision maker (“CODM”) as well as other segment items, extend certain annual disclosures to interim periods, clarify the applicability to single reportable segment entities, permit more than one measure of profit or loss to be reported under certain conditions, and require disclosure of the title and position of the CODM. ASU 2023-07 is effective for annual periods beginning after December 15, 2024 and for interim periods beginning after December 15, 2025, with early adoption permitted. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements.

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Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Summary of Balances of Property and Equipment - Net

The following table summarizes the balances of property and equipment – net (in thousands):

	December 31,
	2023			2022
Land	$	39,567		$	38,551
Marine transportation equipment		5,029,653			4,837,379
Buildings and other equipment		641,871			505,942
Construction in progress		112,947			70,271
	$	5,824,038		$	5,452,143
Accumulated depreciation		(1,962,933	)		(1,818,681	)
Property and equipment – net	$	3,861,105		$	3,633,462

Changes in Goodwill

The following table summarizes the changes in goodwill (in thousands):

	Marine Transportation			Distribution and Services			Total
Balance at December 31, 2022 (gross)		505,784			560,155			1,065,939
Accumulated impairment and amortization		(237,626	)		(389,565	)		(627,191	)
Balance at December 31, 2022 and 2023	$	268,158		$	170,590		$	438,748

Other Intangible Assets and Other Intangible Liabilities

The following table summarizes the balances of other intangible assets and other intangible liabilities (in thousands):

	December 31,
	2023			2022
Other intangible assets – gross	$	184,622		$	203,242
Accumulated amortization		(141,695	)		(151,779	)
Other intangible assets – net	$	42,927		$	51,463
Other intangible liabilities – gross	$	8,800		$	13,860
Accumulated amortization		(8,800	)		(13,280	)
Other intangible liabilities – net	$	—		$	580

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Revenues (Tables)

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue [Table Text Block]

The following table sets forth the Company’s revenues by major source (in thousands):

	Year Ended December 31,
	2023		2022		2021
Marine transportation segment:
Inland transportation	$	1,416,483	$	1,277,010	$	1,005,145
Coastal transportation		305,454		339,957		317,773
	$	1,721,937	$	1,616,967	$	1,322,918
Distribution and services segment:
Commercial and industrial	$	802,474	$	651,566	$	578,011
Oil and gas		567,229		516,221		345,731
	$	1,369,703	$	1,167,787	$	923,742

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Segment Data (Tables)

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

The following tables set forth by reportable segment the revenues, profit or loss, total assets, depreciation and amortization, and capital expenditures attributable to the principal activities of the Company (in thousands):

	Year Ended December 31,
	2023			2022			2021
Revenues:
Marine transportation	$	1,721,937		$	1,616,967		$	1,322,918
Distribution and services		1,369,703			1,167,787			923,742
	$	3,091,640		$	2,784,754		$	2,246,660
Segment profit (loss):
Marine transportation	$	238,943		$	136,184		$	63,015
Distribution and services		114,481			67,037			27,607
Other		(59,299	)		(38,246	)		(381,223	)
	$	294,125		$	164,975		$	(290,601	)
Depreciation and amortization:
Marine transportation	$	184,225		$	177,551		$	185,979
Distribution and services		19,842			16,776			20,573
Other		7,089			7,116			7,166
	$	211,156		$	201,443		$	213,718
Capital expenditures:
Marine transportation	$	255,411		$	147,170		$	84,353
Distribution and services		140,769			21,713			8,104
Other		5,550			3,723			5,558
	$	401,730		$	172,606		$	98,015

	December 31,
	2023		2022
Total assets:
Marine transportation	$	4,454,931	$	4,285,647
Distribution and services		1,156,384		1,041,841
Other		110,882		227,436
	$	5,722,197	$	5,554,924

Other Segment Reporting Information

The following table presents the details of “Other” segment profit (loss) (in thousands):

	Year Ended December 31,
	2023			2022			2021
General corporate expenses	$	(23,341	)	$	(18,614	)	$	(13,803	)
Gain on disposition of assets		5,009			8,279			5,761
Impairments and other charges		—			—			(340,713	)
Interest expense		(52,008	)		(44,588	)		(42,469	)
Other income		11,041			16,677			10,001
	$	(59,299	)	$	(38,246	)	$	(381,223	)

The following table presents the details of “Other” total assets (in thousands):

	December 31,
	2023		2022
General corporate assets	$	108,306	$	225,265
Investment in affiliates		2,576		2,171
	$	110,882	$	227,436

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Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Carrying Values and Fair Values of Debt Outstanding

The following table presents the carrying value and fair value (determined using inputs characteristic of a Level 2 fair value measurement) of debt outstanding (in thousands):

	December 31,
	2023					2022
	Carrying Value			Fair Value		Carrying Value			Fair Value
Revolving Credit Facility due July 29, 2027 (a)	$	44,000		$	44,000	$	—		$	—
Term Loan due July 29, 2027 (a)		170,000			170,000		170,000			170,000
3.29% senior notes due February 27, 2023		—			—		350,000			352,275
4.2% senior notes due March 1, 2028		500,000			475,920		500,000			477,660
3.46% senior notes due January 19, 2033		60,000			49,955		60,000			42,647
3.51% senior notes due January 19, 2033		240,000			200,698		—			—
Credit Line due June 30, 2024		—			—		—			—
Bank notes payable		8,068			8,068		3,292			3,292
		1,022,068			948,641		1,083,292			1,045,874
Unamortized debt discounts and issuance costs (b)		(5,473	)		—		(3,674	)		—
	$	1,016,595		$	948,641	$	1,079,618		$	1,045,874

(a)Variable interest rate of 6.8% and 5.8% at December 31, 2023 and 2022, respectively.

(b)Excludes $1.8 million attributable to the 2027 Revolving Credit Facility included in other assets at December 31, 2022.

Aggregate Payments due on Long-Term Debt

The aggregate payments due on the long-term debt in each of the next five years were as follows (in thousands):

2024	$	8,068
2025		32,500
2026		56,250
2027		125,250
2028		500,000
Thereafter		300,000
	$	1,022,068

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Leases (Tables)

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Future Minimum Lease Payments under Operating Leases

Future minimum lease payments under operating leases that have initial noncancelable lease terms in excess of one year were as follows (in thousands):

2024	$	38,943
2025		27,638
2026		24,945
2027		22,842
2028		18,318
Thereafter		79,755
Total lease payments		212,441
Less: imputed interest		(40,290	)
Operating lease liabilities	$	172,151

Lease, Cost [Table Text Block]

The following table summarizes lease costs (in thousands):

	Year Ended December 31,
	2023			2022			2021
Operating lease cost	$	42,821		$	42,319		$	40,786
Variable lease cost		2,376			1,780			1,793
Short-term lease cost		30,005			25,365			17,914
Sublease income		(3,223	)		(305	)		(1,032	)
Total lease cost	$	71,979		$	69,159		$	59,461

Operating Leases, Weighted Average Discount Rate and Remaining Lease Term

The following table summarizes other supplemental information about the Company’s operating leases:

	December 31,
	2023			2022			2021
Weighted average discount rate		4.4	%		4.1	%		3.8	%
Weighted average remaining lease term	9 years			9 years			9 years

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Stock Award Plans (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Compensation Cost Breakdown in Statement of Earnings

The Company has share-based compensation plans which are described below. The compensation cost that has been charged against earnings for the Company’s stock award plans and the income tax benefit recognized in the statement of earnings for stock awards were as follows (in thousands):

	Year Ended December 31,
	2023		2022		2021
Compensation cost	$	14,941	$	13,865	$	15,713
Income tax benefit	$	3,616	$	3,533	$	4,410

Stock Option Valuation Assumptions

The key input variables used in valuing the stock options granted were as follows:

	Year Ended December 31,
	2023
Dividend yield	None
Average risk-free interest rate		3.7	%
Stock price volatility		35	%
Estimated option term	7 years

Employee Plan [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Stock Option Activity

The following is a summary of the stock option activity under the employee plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		396,165		$	70.06
Exercised		(117,896	)	$	60.84
Expired		(23,024	)	$	73.66
Outstanding at December 31, 2023		255,245		$	74.00

Outstanding and Exercisable Stock Options

The following table summarizes information about the Company’s outstanding and exercisable stock options under the employee plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)
$64.89		15,500		1.3	$	64.89				15,500	$	64.89
$73.29 – $75.50		233,040		2.1	$	74.29				233,040	$	74.29
$84.90		6,705		2.3	$	84.90				6,705	$	84.90
$64.89 – $84.90		255,245		2.0	$	74.00	$	1,187		255,245	$	74.00	$	1,187

RSU Activity

The following is a summary of RSU activity under the employee plan described above:

	Unvested RSUs			Weighted Average Grant Date Fair Value Per Unit
Nonvested balance at December 31, 2022		558,819		$	62.13
Granted		184,440		$	72.23
Vested		(161,550	)	$	64.85
Forfeited		(27,105	)	$	63.68
Nonvested balance at December 31, 2023		554,604		$	64.61

Director Plan [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Stock Option Activity

The following is a summary of the stock option activity under the director plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		56,480		$	86.19
Granted		3,865		$	72.83
Exercised		—		$	—
Expired		(30,000	)	$	80.04
Outstanding at December 31, 2023		30,345		$	90.57

Outstanding and Exercisable Stock Options

The following table summarizes information about the Company’s outstanding and exercisable stock options under the director plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)
$70.65 – $73.57		7,053		6.6	$	71.85				6,278	$	71.75
$84.90 – $85.30		5,292		4.8	$	85.10				5,292	$	85.10
$99.52		18,000		0.3	$	99.52				18,000	$	99.52
$70.65 – $99.52		30,345		2.6	$	90.57	$	47		29,570	$	91.04	$	42

Restricted Stock Award Activity

The following is a summary of the restricted stock award activity under the director plan described above:

	Unvested Restricted Stock Award Shares			Weighted Average Grant Date Fair Value Per Share
Nonvested balance at December 31, 2022		1,698		$	65.36
Granted		31,526		$	72.67
Vested		(32,604	)	$	72.29
Nonvested balance at December 31, 2023		620		$	72.65

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Taxes on Income (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Earnings (Loss) Before Taxes

Earnings (loss) before taxes on income and details of the provision (benefit) for taxes on income were as follows (in thousands):

	Year Ended December 31,
	2023			2022		2021
Earnings (loss) before taxes on income:
United States	$	293,011		$	164,590	$	(290,181	)
Foreign		1,114			385		(420	)
	$	294,125		$	164,975	$	(290,601	)
Provision (benefit) for taxes on income:
U.S. Federal:
Current	$	(41	)	$	513	$	(460	)
Deferred		61,205			34,980		(48,843	)
	$	61,164		$	35,493	$	(49,303	)
U.S. State:
Current	$	5,498		$	3,793	$	1,560
Deferred		4,093			2,802		4,424
	$	9,591		$	6,595	$	5,984
Foreign:
Current	$	465		$	126	$	(511	)
	$	465		$	126	$	(511	)
Consolidated:
Current	$	5,922		$	4,432	$	589
Deferred		65,298			37,782		(44,419	)
	$	71,220		$	42,214	$	(43,830	)

Effective Income Tax Rate Reconciliation

The Company’s provision (benefit) for taxes on income varied from the statutory federal income tax rate due to the following:

	Year Ended December 31,
	2023			2022			2021
United States income tax statutory rate		21.0	%		21.0	%		21.0	%
State and local taxes, net of federal benefit		2.6			3.1			(1.7	)
Other – net		0.6			1.5			(4.2	)
		24.2	%		25.6	%		15.1	%

Deferred Tax Assets and Liabilities

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities were as follows (in thousands):

	December 31,
	2023			2022
Deferred tax assets:
Allowance for doubtful accounts	$	1,549		$	1,556
Inventory		10,500			11,679
Insurance accruals		6,077			4,856
Deferred compensation		11,441			7,703
Unrealized gain on defined benefit plans		(9,982	)		(5,532	)
Goodwill and other intangibles		39,719			52,847
Operating loss carryforwards		52,082			79,699
Retirement benefits		3,548			5,472
Other		13,467			9,962
		128,401			168,242
Valuation allowances		(22,073	)		(19,960	)
		106,328			148,282
Deferred tax liabilities:
Property		(695,233	)		(671,830	)
Deferred state taxes		(90,457	)		(87,445	)
Other		(17,195	)		(14,891	)
		(802,885	)		(774,166	)
	$	(696,557	)	$	(625,884	)

Reconciliation of Liability for Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of the liability for unrecognized tax benefits is as follows (in thousands):

	Year Ended December 31,
	2023			2022			2021
Balance at beginning of year	$	662		$	737		$	783
Additions based on tax positions related to the current year		—			13			13
Additions for tax positions of prior years		—			66			281
Reductions for tax positions of prior years		(14	)		(154	)		(340	)
Balance at end of year	$	648		$	662		$	737

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Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Schedule of Loss Per Share

The following table presents the components of basic and diluted earnings (loss) per share (in thousands, except per share amounts):

	Year Ended December 31,
	2023			2022			2021
Net earnings (loss) attributable to Kirby	$	222,935		$	122,291		$	(246,954	)
Undistributed earnings allocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — basic		222,873			122,258			(246,954	)
Undistributed earnings allocated to restricted shares		62			33			—
Undistributed earnings reallocated to restricted shares		(62	)		(33	)		—
Earnings (loss) available to Kirby common stockholders — diluted	$	222,873		$	122,258		$	(246,954	)
Shares outstanding:
Weighted average common stock issued and outstanding		59,548			60,055			60,099
Weighted average unvested restricted stock		(17	)		(17	)		(46	)
Weighted average common stock outstanding — basic		59,531			60,038			60,053
Dilutive effect of stock options and restricted stock units		326			291			—
Weighted average common stock outstanding — diluted		59,857			60,329			60,053
Net earnings (loss) per share attributable to Kirby common stockholders:
Basic	$	3.74		$	2.04		$	(4.11	)
Diluted	$	3.72		$	2.03		$	(4.11	)

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Inventories (Tables)

12 Months Ended

Dec. 31, 2023

Inventory Disclosure [Abstract]

Schedule of Inventories, Net

The following table presents the details of inventories — net (in thousands):

	December 31,
	2023		2022
Finished goods	$	351,050	$	358,702
Work in process		103,339		103,146
	$	454,389	$	461,848

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Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2023

Defined Benefit Plan Disclosure [Line Items]

Asset Allocation

The aggregate fair value of plan assets of the Company’s pension plans was $375.9 million and $341.1 million at December 31, 2023 and 2022, respectively. Pension assets were allocated among asset categories as follows:

	December 31,						Current Minimum, Target and Maximum
Asset Category	2023			2022			Allocation Policy
U.S. equity securities		51	%		50	%		45	%	— 50%	— 55%
International equity securities		20			20			12	%	— 20%	— 28%
Debt securities		29			30			20	%	— 30%	— 40%
Cash and cash equivalents		—			—			0	%	— 0%	— 0%
		100	%		100	%

Change in Benefit Obligation

The following table presents the change in benefit obligation and plan assets for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits												Other Postretirement Benefits
	Pension Plans						SERP						Postretirement Welfare Plan
	2023			2022			2023			2022			2023			2022
Change in benefit obligation
Benefit obligation at beginning of year	$	339,509		$	495,272		$	833		$	1,033		$	432		$	582
Service cost		3,695			6,538			—			—			—			—
Interest cost		18,356			14,779			43			29			22			17
Actuarial (gain) loss		13,241			(158,816	)		91			(74	)		65			(58	)
Gross benefits paid		(32,052	)		(12,665	)		(153	)		(155	)		(104	)		(109	)
Settlements		—			(5,599	)		—			—			—			—
Benefit obligation at end of year	$	342,749		$	339,509		$	814		$	833		$	415		$	432
Accumulated benefit obligation at end of year	$	326,987		$	325,274		$	814		$	833		$	415		$	432
Weighted-average assumption used to determine benefit obligation at end of year
Discount rate (a)	5.1%/5.2%				5.5	%		5.1	%		5.5	%		5.1	%		5.5	%
Rate of compensation increase	Service-based table			Service-based table				—			—			—			—
Health care cost trend rate
Initial rate		—			—			—			—			6.25	%		6.50	%
Ultimate rate		—			—			—			—			5.0	%		5.0	%
Years to ultimate		—			—			—			—		2029			2029
Change in plan assets
Fair value of plan assets at beginning of year	$	341,061		$	430,821		$	—		$	—		$	—		$	—
Actual return on plan assets		58,734			(72,402	)		—			—			—			—
Employer contribution		8,174			906			153			155			104			109
Gross benefits paid		(32,052	)		(12,665	)		(153	)		(155	)		(104	)		(109	)
Settlements		—			(5,599	)		—			—			—			—
Fair value of plan assets at end of year	$	375,917		$	341,061		$	—		$	—		$	—		$	—

(a)The 2023 discount rate was 5.1% for the Kirby Pension Plan and 5.2% for the Higman Pension Plan. The 2022 discount rate was 5.5% for both the Kirby Pension Plan and the Higman Pension Plan.

Funded Status at End of Year

The following table presents the funded status and amounts recognized in the Company’s consolidated balance sheet for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits												Other Postretirement Benefits
	Pension Plans						SERP						Postretirement Welfare Plan
	2023			2022			2023			2022			2023			2022
Funded status at end of year
Fair value of plan assets	$	375,917		$	341,061		$	—		$	—		$	—		$	—
Benefit obligations		(342,749	)		(339,509	)		(814	)		(833	)		(415	)		(432	)
Funded status and amount recognized at end of year	$	33,168		$	1,552		$	(814	)	$	(833	)	$	(415	)	$	(432	)
Amounts recognized in the consolidated balance sheets
Noncurrent asset		42,698			18,695			—			—			—			—
Current liability		—			—			(106	)		(106	)		(46	)		(49	)
Long-term liability		(9,530	)		(17,143	)		(708	)		(727	)		(369	)		(383	)
Amounts recognized in accumulated other comprehensive income
Net actuarial (gain) loss	$	(48,033	)	$	(25,449	)	$	391		$	324		$	(1,890	)	$	(2,299	)
Prior service cost (credit)		—			—			—			—			—			—
Accumulated other compensation income	$	(48,033	)	$	(25,449	)	$	391		$	324		$	(1,890	)	$	(2,299	)

Expected Cash Flows for the Defined Benefit Plans and Postretirement Benefit Plan

The following table presents the expected cash flows for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

	Pension Benefits								Other Postretirement Benefits
	Pension Plans				SERP				Postretirement Welfare Plan
	2023		2022		2023		2022		2023		2022
Expected employer contributions
First year	$	1,770	$	8,374	$	—	$	—	$	—	$	—
Expected benefit payments (gross)
Year one	$	16,696	$	16,312	$	108	$	108	$	47	$	50
Year two		17,513		16,899		103		104		46		49
Year three		18,169		17,808		98		99		44		47
Year four		19,096		18,650		93		94		43		45
Year five		19,860		19,707		88		90		41		43
Next five years		108,717		110,417		337		359		167		176

Pension Benefits [Member]

Defined Benefit Plan Disclosure [Line Items]

Net Periodic Benefit Cost

The components of net periodic benefit cost and other changes in plan assets and benefit obligations recognized in other comprehensive income for the Company’s defined benefit plans were as follows (in thousands):

	Pension Benefits
	Pension Plans									SERP
	2023			2022			2021			2023			2022			2021
Components of net periodic benefit cost
Service cost	$	3,695		$	6,538		$	7,961		$	—		$	—		$	—
Interest cost		18,356			14,779			14,239			43			29			31
Expected return on plan assets		(22,910	)		(28,399	)		(26,244	)		—			—			—
Amortization of actuarial loss		—			34			4,193			23			30			40
Net periodic benefit cost		(859	)		(7,048	)		149			66			59			71
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Current year actuarial (gain) loss		(22,583	)		(58,015	)		(44,583	)		91			(74	)		(12	)
Recognition of actuarial loss		—			(34	)		(4,193	)		(23	)		(30	)		(40	)
Total recognized in other comprehensive income		(22,583	)		(58,049	)		(48,776	)		68			(104	)		(52	)
Total recognized in net periodic benefit cost and other comprehensive income	$	(23,442	)	$	(65,097	)	$	(48,627	)	$	134		$	(45	)	$	19
Weighted average assumptions used to determine net periodic benefit cost
Discount rate (a)		5.5	%	3.0% / 3.1%			2.8% / 2.9%				5.5	%		3.0	%		2.8	%
Expected long-term rate of return on plan assets		6.75	%		6.75	%		6.75	%		—			—			—
Rate of compensation increase	Service-based table			Service-based table			Service-based table				—			—			—

(a)The 2023 discount rate for benefit cost is 5.5% for both the Kirby Pension Plan and the Higman Pension Plan. The 2022 discount rate for benefit cost is 3.0% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan.

Other Postretirement Benefits [Member]

Defined Benefit Plan Disclosure [Line Items]

Net Periodic Benefit Cost

The components of net periodic benefit cost and other changes in benefit obligations recognized in other comprehensive income for the Company’s postretirement benefit plan were as follows (in thousands):

	Other Postretirement Benefits
	Postretirement Welfare Plan
	2023			2022			2021
Components of net periodic benefit cost
Interest cost	$	22		$	17		$	17
Amortization of actuarial gain		(344	)		(394	)		(451	)
Net periodic benefit cost		(322	)		(377	)		(434	)
Other changes in benefit obligations recognized in other comprehensive income
Current year actuarial loss (gain)		65			(58	)		104
Recognition of actuarial gain		344			394			451
Total recognized in other comprehensive income		409			336			555
Total recognized in net periodic benefit cost and other    comprehensive income	$	87		$	(41	)	$	121
Weighted average assumptions used to determine net periodic benefit cost
Discount rate		5.5	%		3.0	%		2.8	%
Health care cost trend rate:
Initial rate		6.50	%		6.25	%		6.50	%
Ultimate rate		5.0	%		5.0	%		5.0	%
Years to ultimate	2029			2027			2025

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Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2023

Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]

Changes in Other Comprehensive Income (Loss)

The Company’s changes in other comprehensive income (loss) were as follows (in thousands):

	Year Ended December 31,
	2023									2022									2021
	Gross Amount			Income Tax (Provision) Benefit			Net Amount			Gross Amount			Income Tax (Provision) Benefit			Net Amount			Gross Amount			Income Tax Provision			Net Amount
Pension and postretirement benefits (a):
Amortization of net actuarial (gain) loss	$	(321	)	$	78		$	(243	)	$	(330	)	$	81		$	(249	)	$	3,782		$	(952	)	$	2,830
Actuarial gain		22,438			(5,467	)		16,971			58,147			(14,030	)		44,117			44,491			(10,774	)		33,717
Foreign currency translation adjustments		1,425			—			1,425			(1,049	)		—			(1,049	)		(1,061	)		—			(1,061	)
Total	$	23,542		$	(5,389	)	$	18,153		$	56,768		$	(13,949	)	$	42,819		$	47,212		$	(11,726	)	$	35,486

(a)Actuarial gains (losses) are amortized into other income (expense). (See Note 12 – Retirement Plans)

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Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Receivables [Abstract]
Accruals for revenues earned included in accounts receivable	$ 136,300	$ 139,500
Receivables from insurance companies to cover claims in excess included in accounts receivable	$ 29,600	27,700
Drydocking on Ocean-Going Vessels [Abstract]
Period in which recertification of ocean going vessels occur twice	5 years
Recognized amortization of major maintenance costs	$ 29,000	29,000	$ 33,200
Capitalized interest excluded from interest expense	$ 0	$ 0	$ 0
Minimum [Member]
Drydocking on Ocean-Going Vessels [Abstract]
Period of amortization of shipyard costs	30 months
Maximum [Member]
Drydocking on Ocean-Going Vessels [Abstract]
Period of amortization of shipyard costs	60 months
Marine Transportation Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Useful Life	5 years
Marine Transportation Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Useful Life	40 years
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Useful Life	10 years
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Useful Life	40 years
Other Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Useful Life	2 years
Other Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Useful Life	10 years

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Summary of Significant Accounting Policies, Summary of Balances of Property and Equipment - Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,824,038	$ 5,452,143
Accumulated depreciation	(1,962,933)	(1,818,681)
Property and equipment - net	3,861,105	3,633,462
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	39,567	38,551
Marine Transportation Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,029,653	4,837,379
Buildings and Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	641,871	505,942
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 112,947	$ 70,271

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Summary of Significant Accounting Policies, Goodwill and Other Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Balance (gross)	$ 1,065,939
Accumulated impairment and amortization	(627,191)
Balance	438,748
Balance (gross)		$ 1,065,939
Accumulated impairment and amortization	(627,191)	(627,191)
Balance	438,748	438,748
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Other intangible assets - gross	184,622	203,242
Accumulated amortization	(141,695)	(151,779)
Other intangible assets - net	42,927	51,463
Other intangible liabilities - gross	8,800	13,860
Accumulated amortization	(8,800)	(13,280)
Other intangible liabilities - net	0	580
Amortization of Intangible Assets	8,100	7,600	$ 7,800
Intangible Assets and liabilities, Estimated Amortization Expense, Fiscal Year Maturity [Abstract]
2024	8,500
2025	8,500
2026	6,300
2027	5,000
2028	3,500
Thereafter	$ 11,100
Weighted average amortization period for intangible assets and liabilities	7 years
Marine Transportation Segment [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Balance (gross)	$ 505,784
Accumulated impairment and amortization	(237,626)
Balance	268,158
Balance (gross)		505,784
Accumulated impairment and amortization	(237,626)	(237,626)
Balance	268,158	268,158
Distribution and Services Segment [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Balance (gross)	560,155
Accumulated impairment and amortization	(389,565)
Balance	170,590
Balance (gross)		560,155
Accumulated impairment and amortization	(389,565)	(389,565)
Balance	$ 170,590	$ 170,590

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Summary of Significant Accounting Policies, Revenue Recognition through Accrued Insurance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Insurance [Abstract]
Accrued insurance liabilities	$ 52.5	$ 39.1	$ 37.8
Marine Transportation Segment [Member] | Minimum [Member]
Revenue Recognition [Abstract]
Range of term contracts	1 year
Marine Transportation Segment [Member] | Maximum [Member]
Revenue Recognition [Abstract]
Range of term contracts	3 years

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Acquisitions (Details) $ in Thousands				9 Months Ended	12 Months Ended
	Jul. 14, 2023 USD ($) Barge Barrels	Mar. 31, 2022 USD ($)	Oct. 04, 2021 USD ($)	Sep. 30, 2023 USD ($) Barge	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) Vessel
Restructuring Cost and Reserve [Line Items]
Cash paid for acquisition					$ 401,730	$ 172,606	$ 98,015
Inland Tank Barges [Member]
Restructuring Cost and Reserve [Line Items]
Number of tank barges | Barge	23			4
Total capacity of barrels | Barrels	265,000
Cash paid for acquisition	$ 37,000
Number of maritime vessels acquired | Vessel							4
Cash paid for acquisition				$ 500			$ 7,500
Average age	14 years
Energy Storage System [Member]
Restructuring Cost and Reserve [Line Items]
Cash paid for acquisition			$ 1,600
Gearbox Repair [Member]
Restructuring Cost and Reserve [Line Items]
Cash paid for acquisition		$ 3,900

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Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Abstract]
Revenues by major source	$ 3,091,640	$ 2,784,754	$ 2,246,660
Revenue recognized	84,000	61,700	40,900
Marine Transportation [Member]
Disaggregation of Revenue [Abstract]
Revenues by major source	1,721,937	1,616,967	1,322,918
Marine Transportation [Member] | Inland Transportation [Member]
Disaggregation of Revenue [Abstract]
Revenues by major source	1,416,483	1,277,010	1,005,145
Marine Transportation [Member] | Coastal Transportation [Member]
Disaggregation of Revenue [Abstract]
Revenues by major source	305,454	339,957	317,773
Distribution and Services [Member]
Disaggregation of Revenue [Abstract]
Revenues by major source	1,369,703	1,167,787	923,742
Distribution and Services [Member] | Commercial and Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenues by major source	802,474	651,566	578,011
Distribution and Services [Member] | Oil and Gas [Member]
Disaggregation of Revenue [Abstract]
Revenues by major source	$ 567,229	$ 516,221	$ 345,731

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Revenues, Remaining Performance Obligation (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Contract assets	$ 0	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-12-31
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year

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Segment Data (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Segment	2
Revenues [Abstract]
Revenues	$ 3,091,640	$ 2,784,754	$ 2,246,660
Segment profit (loss)	294,125	164,975	(290,601)
Total assets	5,722,197	5,554,924
Depreciation and amortization	211,156	201,443	213,718
Capital expenditures	401,730	172,606	98,015
Other segment disclosures [Abstract]
Gain on disposition of assets	5,009	8,279	5,761
Interest expense	(52,008)	(44,588)	(42,469)
Earnings (loss) before taxes on income	294,125	164,975	(290,601)
Other Assets [Abstract]
Investment in affiliates	2,576	2,171
Marine Transportation [Member]
Revenues [Abstract]
Revenues	1,721,937	1,616,967	1,322,918
Distribution and Services [Member]
Revenues [Abstract]
Revenues	1,369,703	1,167,787	923,742
Other [Member]
Revenues [Abstract]
Segment profit (loss)	(59,299)	(38,246)	(381,223)
Total assets	110,882	227,436
Depreciation and amortization	7,089	7,116	7,166
Capital expenditures	5,550	3,723	5,558
Other segment disclosures [Abstract]
General corporate expenses	(23,341)	(18,614)	(13,803)
Gain on disposition of assets	5,009	8,279	5,761
Impairments and other charges	0	0	(340,713)
Interest expense	(52,008)	(44,588)	(42,469)
Other income	11,041	16,677	10,001
Earnings (loss) before taxes on income	(59,299)	(38,246)	(381,223)
Other Assets [Abstract]
General corporate assets	108,306	225,265
Investment in affiliates	2,576	2,171
Total other assets	110,882	227,436
Reportable Segments [Member] | Marine Transportation [Member]
Revenues [Abstract]
Revenues	1,721,937	1,616,967	1,322,918
Segment profit (loss)	238,943	136,184	63,015
Total assets	4,454,931	4,285,647
Depreciation and amortization	184,225	177,551	185,979
Capital expenditures	255,411	147,170	84,353
Other segment disclosures [Abstract]
Earnings (loss) before taxes on income	238,943	136,184	63,015
Reportable Segments [Member] | Distribution and Services [Member]
Revenues [Abstract]
Revenues	1,369,703	1,167,787	923,742
Segment profit (loss)	114,481	67,037	27,607
Total assets	1,156,384	1,041,841
Depreciation and amortization	19,842	16,776	20,573
Capital expenditures	140,769	21,713	8,104
Other segment disclosures [Abstract]
Earnings (loss) before taxes on income	114,481	67,037	27,607
Intersegment Eliminations [Member]
Revenues [Abstract]
Revenues	39,800	31,900	23,600
Segment profit (loss)	4,000	3,200	2,400
Other segment disclosures [Abstract]
Earnings (loss) before taxes on income	$ 4,000	$ 3,200	$ 2,400

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Long-Term Debt, Carrying Value and Fair Value of Debt Outstanding (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 29, 2022	Dec. 31, 2023	Dec. 31, 2022
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		$ 1,022,068	$ 1,083,292
Fair value		948,641	1,045,874
Unamortized debt discounts and issuance costs		(5,473)	(3,674)
Long-term debt		1,016,595	1,079,618
Debt Instrument, Basis Spread on Variable Rate	0.50%
Amount excluded on unamortized debt discounts and issuance costs			1,800
3.29% Senior Notes Due February, 27 2023 [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		0	350,000
Fair value		$ 0	352,275
Interest rate		3.29%
Maturity Date		Feb. 27, 2023
4.2% Senior Notes Due March 1, 2028 [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		$ 500,000	500,000
Fair value		$ 475,920	477,660
Interest rate		4.20%
Maturity Date		Mar. 01, 2028
3.46% Senior Notes Due January 19, 2033 [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		$ 60,000	60,000
Fair value		$ 49,955	42,647
Interest rate		3.46%
Maturity Date		Jan. 19, 2033
3.51% senior notes due January 19, 2033 [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		$ 240,000	0
Fair value		$ 200,698	0
Interest rate		3.51%
Maturity Date		Jan. 19, 2033
Credit Line Due June 30, 2024 [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		$ 0	0
Fair value		$ 0	0
Maturity Date		Jun. 30, 2024
Bank Note Payable [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		$ 8,068	3,292
Fair value		8,068	3,292
Revolving Credit Facility [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		44,000	0
Fair value		$ 44,000	0
Maturity Date		Jul. 29, 2027
Term Loan [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Long-term debt	$ 250,000
Term Loan Due July 29,2027 [Member]
Carrying Value and Fair Value of Debt Outstanding [Abstract]
Carrying value		$ 170,000	170,000
Fair value		$ 170,000	$ 170,000
Debt Instrument, Basis Spread on Variable Rate		6.80%	5.80%
Maturity Date		Jul. 29, 2027

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Long-Term Debt, Schedule of Aggregate Payments Due on Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
2024	$ 8,068
2025	32,500
2026	56,250
2027	125,250
2028	500,000
Thereafter	300,000
Carrying value	$ 1,022,068	$ 1,083,292

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Long-Term Debt (Details) - USD ($)					1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2025	Jul. 19, 2023	Jan. 19, 2023	Feb. 03, 2022	Jul. 29, 2022	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Long-term Debt [Abstract]
Payments on long-term debt							$ 350,000,000	$ 395,000,000	$ 60,000,000
Term loan						$ 1,079,618,000	1,016,595,000	1,079,618,000
Unpaid balance					$ 43,800,000
Debt Instrument, Basis Spread on Variable Rate					0.50%
Senior Notes Due March 1, 2028 [Member]
Long-term Debt [Abstract]
Long term debt, face amount							$ 500,000,000
Interest rate							4.20%
Maturity Date							Mar. 01, 2028
Debt Instrument, Periodic Payment, Interest							$ 10,500,000
Senior Notes Series B Due February 27, 2023 [Member]
Long-term Debt [Abstract]
Interest rate							3.29%
Maturity Date							Feb. 27, 2023
3.46 Series A Notes Due January 19, 2023 [Member]
Long-term Debt [Abstract]
Long term debt, face amount				$ 60,000,000
Interest rate				3.46%
Maturity Date				Jan. 19, 2033
3.51 Series B Notes Due January 19, 2023 [Member]
Long-term Debt [Abstract]
Long term debt, face amount				$ 240,000,000
Interest rate				3.51%
Maturity Date				Jan. 19, 2033
Debt Instrument, Periodic Payment, Interest		$ 5,300,000	$ 500,000
SOFR [Member]
Long-term Debt [Abstract]
Interest rate					1.00%
Revolving Credit Facility [Member]
Long-term Debt [Abstract]
Maturity Date							Jul. 29, 2027
Maximum borrowing capacity					$ 500,000,000		$ 850,000,000
Credit facility, amount outstanding							6,000
Available borrowing capacity					35,000,000		$ 456,000,000
Commitment Amount					$ 25,000
Revolving Credit Facility [Member] | SOFR [Member]
Long-term Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate					137.50%
Revolving Credit Facility [Member] | Base Rate [Member]
Long-term Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate					37.50%
Term Loan [Member]
Long-term Debt [Abstract]
Payments on long-term debt					$ 250,000,000	80,000,000
Term loan					$ 250,000,000
Credit facility, expiration date					Jul. 29, 2027		Mar. 27, 2024
Term Loan [Member] | Forecast [Member]
Long-term Debt [Abstract]
Payments on long-term debt	$ 0
Line Of Credit [Member]
Long-term Debt [Abstract]
Maximum borrowing capacity							$ 10,000,000
Credit facility, expiration date							Jun. 30, 2024
Credit facility, amount outstanding							$ 7,300,000
Available borrowing capacity							2,700,000
Secured Debt [Member]
Long-term Debt [Abstract]
Short-Term Debt						$ 3,300,000	$ 8,100,000	$ 3,300,000
Unsecured Debt [Member]
Long-term Debt [Abstract]
Long term debt, face amount				$ 300,000,000

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Leases, Future Minimum Lease Payments Under Operating Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Leases [Abstract]
Percentage of costs relate to service costs for leased towing vessels	70.00%
Future Minimum Lease Payments Under Operating Leases [Abstract]
2024	$ 38,943
2025	27,638
2026	24,945
2027	22,842
2028	18,318
Thereafter	79,755
Total lease payments	212,441
Less: imputed interest	(40,290)
Operating lease liabilities	$ 172,151

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Leases, Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lease, Cost [Abstract]
Operating lease cost	$ 42,821	$ 42,319	$ 40,786
Variable lease cost	2,376	1,780	1,793
Short-term lease cost	30,005	25,365	17,914
Sublease income	(3,223)	(305)	(1,032)
Total lease cost	$ 71,979	$ 69,159	$ 59,461

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Leases, Other Supplemental Information (Details)	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other Supplemental Information about Operating Leases [Abstract]
Weighted average discount rate	4.40%	4.10%	3.80%
Weighted average remaining lease term	9 years	9 years	9 years

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Impairments and Other Charges (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2021 USD ($)	Dec. 31, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Impairment Effects on Earnings Per Share [Line Items]
Proceeds from sale of assets		$ 26,081	$ 36,905	$ 51,342
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]	Asset Impairment Charges
Marine Transportation [Member]
Impairment Effects on Earnings Per Share [Line Items]
Number of reporting units | Segment		1
Goodwill impairment charge	$ 219,100
Level 3 [Member] | Marine Transportation [Member]
Impairment Effects on Earnings Per Share [Line Items]
Non-cash pre-tax impairment charge	24,200
HAWAII | Marine Transportation [Member]
Impairment Effects on Earnings Per Share [Line Items]
Proceeds from sale of assets	17,200
Impairment of Intangible Assets, Finite-Lived	$ 97,500

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Stock Award Plans, Compensation Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Compensation cost	$ 14,941	$ 13,865	$ 15,713
Income tax benefit	$ 3,616	$ 3,533	$ 4,410

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Stock Award Plans, Employee Plan Stock Option Activity (Details) - Employee Stock Award Plan [Member]	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Employee Stock Option [Member]
Stock Award Plan Information [Abstract]
Term of grant	7 years
Vesting period	3 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at Period Start (in shares)	396,165
Exercised (in shares)	(117,896)
Expired (in shares)	(23,024)
Outstanding at Period End (in shares)	255,245
Weighted Average Exercise Price [Abstract]
Outstanding at Period Start (in dollars per share) | $ / shares	$ 70.06
Exercised (in dollars per share) | $ / shares	60.84
Expired (in dollars per share) | $ / shares	73.66
Outstanding at Period End (in dollars per share) | $ / shares	$ 74
Stock Appreciation Rights (SARs)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at Period End (in shares)	0
Restricted Stock Units (RSUs) [Member]
Stock Award Plan Information [Abstract]
Vesting period	5 years

XML

Stock Award Plans, Employee Plan Outstanding and Exercisable Options (Details) - Employee Stock Award Plan [Member] - Employee Stock Option [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
First Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)	$ 64.89
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	15,500
Weighted Average Remaining Contractual Life	1 year 3 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 64.89
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	15,500
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 64.89
Second Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)	73.29
Range of Exercise Prices, upper limit (in dollars per share)	$ 75.5
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	233,040
Weighted Average Remaining Contractual Life	2 years 1 month 6 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 74.29
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	233,040
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 74.29
Third Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)	$ 84.9
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	6,705
Weighted Average Remaining Contractual Life	2 years 3 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 84.9
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	6,705
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 84.9
Full Exercise Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)	64.89
Range of Exercise Prices, upper limit (in dollars per share)	$ 84.9
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	255,245
Weighted Average Remaining Contractual Life	2 years
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 74
Aggregate Intrinsic Value, Options Outstanding | $	$ 1,187
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	255,245
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 74
Aggregate Intrinsic Value, Options Exercisable | $	$ 1,187

XML

Stock Award Plans, Employee Plan Restricted Stock Award Activity (Details) - Employee Stock Award Plan [Member] - Restricted Stock [Member] - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period	0	0	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number	0	0

XML

Stock Award Plans, Employee Plan RSU Activity (Details) - Employee Stock Award Plan [Member] - Restricted Stock Units (RSUs) [Member] - $ / shares	1 Months Ended	12 Months Ended
	Feb. 29, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested balance beginning of period (in shares)		558,819
Granted (in shares)		184,440
Vested (in shares)		(161,550)
Forfeited (in shares)		(27,105)
Nonvested balance end of period (in shares)		554,604	558,819
Weighted Average Grant Date Fair Value Per Share [Abstract]
Nonvested balance beginning of period (in dollars per share)		$ 62.13
Granted (in dollars per share)		72.23	$ 66.13	$ 51.36
Vested (in dollars per share)		64.85
Forfeited or expired (in dollars per share)		63.68
Nonvested balance end of period (in dollars per share)		$ 64.61	$ 62.13
Vesting period		5 years
Forecast [Member]
Weighted Average Grant Date Fair Value Per Share [Abstract]
Vesting period	5 years
Subsequent Event [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)	164,793

XML

Stock Award Plans, Director Plan Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
2005 Stock and Incentive Plan [Member]
Stock Award Plan Information [Abstract]
Shares available for future grants (in shares)	2,045,694
Director Plan [Member]
Stock Award Plan Information [Abstract]
Shares available for future grants (in shares)	369,360
Director Plan [Member] | Employee Stock Option
Stock Award Plan Information [Abstract]
Term of grant	10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at Period Start (in shares)	56,480
Granted (in shares)	3,865
Exercised (in shares)	0
Expired (in shares)	(30,000)
Outstanding at Period End (in shares)	30,345
Weighted Average Exercise Price [Abstract]
Outstanding at Period Start (in dollars per share) | $ / shares	$ 86.19
Granted (in dollars per share) | $ / shares	72.83
Exercised (in dollars per share) | $ / shares	0
Expired (in dollars per share) | $ / shares	80.04
Outstanding at Period End (in dollars per share) | $ / shares	$ 90.57
Director Plan [Member] | Restricted Stock [Member]
Stock Award Plan Information [Abstract]
Vesting period	6 months

XML

Stock Award Plans, Director Plan Outstanding and Exercisable Options (Details) - Director Plan [Member] - Employee Stock Option [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
First Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)	$ 70.65
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 73.57
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	7,053
Weighted Average Remaining Contractual Life	6 years 7 months 6 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 71.85
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	6,278
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 71.75
Second Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)	84.9
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 85.3
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	5,292
Weighted Average Remaining Contractual Life	4 years 9 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 85.1
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	5,292
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 85.1
Third Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)	$ 99.52
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	18,000
Weighted Average Remaining Contractual Life	3 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 99.52
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	18,000
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 99.52
Full Exercise Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)	70.65
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 99.52
Options Outstanding [Abstract]
Number Outstanding (in shares) | shares	30,345
Weighted Average Remaining Contractual Life	2 years 7 months 6 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 90.57
Aggregate Intrinsic Value, Options Outstanding | $	$ 47
Options Exercisable [Abstract]
Number Exercisable (in shares) | shares	29,570
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 91.04
Aggregate Intrinsic Value, Options Exercisable | $	$ 42

XML

Stock Award Plans, Director Plan Restricted Stock Award Activity (Details) - Director Plan [Member] - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested balance beginning of period (in shares)	1,698
Granted (in shares)	31,526
Vested (in shares)	(32,604)
Nonvested balance end of period (in shares)	620	1,698
Weighted Average Grant Date Fair Value Per Share [Abstract]
Nonvested balance beginning of period (in dollars per share)	$ 65.36
Granted (in dollars per share)	72.67	$ 64.61	$ 65.13
Vested (in dollars per share)	72.29
Nonvested balance end of period (in dollars per share)	$ 72.65	$ 65.36

XML

Stock Award Plans, All Plans Options and Restricted Stock Award Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Plans Combined Disclosure [Abstract]
Intrinsic value of stock options exercised	$ 1,500,000	$ 400,000	$ 100,000
Intrinsic value of restricted stock vesting	2,500,000	3,200,000	5,300,000
Tax benefit from restricted stock vesting	600,000	800,000	1,500,000
Employee Stock Award Plan [Member]
Share-based Compensation Plans Combined Disclosure [Abstract]
Intrinsic value of restricted stock vesting	10,900,000	9,500,000	4,400,000
Tax benefit from restricted stock vesting	$ 2,600,000	$ 2,400,000	$ 1,200,000
Fair value of stock options granted	0	0	0
Director Plan [Member]
Share-based Compensation Plans Combined Disclosure [Abstract]
Fair value of stock options granted (in dollars per share)	$ 32.33
Fair value of stock options granted	$ 100,000
Employee Stock Option
Fair Value Assumptions [Abstract]
Dividend yield	0.00%
Average risk-free interest rate	3.70%
Stock price volatility	35.00%
Estimated option term	7 years
Restricted Stock [Member]
Share-based Compensation Plans Combined Disclosure [Abstract]
Unrecognized compensation cost related to unvested awards	$ 45,000
Weighted average period of recognition in years	2 months 12 days
Restricted Stock [Member] | Director Plan [Member]
Share-based Compensation Plans Combined Disclosure [Abstract]
Vesting (in shares)	32,604
RSUs [Member]
Share-based Compensation Plans Combined Disclosure [Abstract]
Unrecognized compensation cost related to unvested awards	$ 15,300,000
Weighted average period of recognition in years	2 years 8 months 12 days
RSUs [Member] | Employee Stock Award Plan [Member]
Share-based Compensation Plans Combined Disclosure [Abstract]
Vesting (in shares)	161,550

XML

Taxes on Income, Earnings (Loss) Before Taxes (Details) - USD ($) $ in Thousands			12 Months Ended
	Nov. 13, 2021	Nov. 12, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Apr. 30, 2023
Earnings (loss) before taxes on income [Abstract]
Earnings (loss) before taxes on income			$ 294,125	$ 164,975	$ (290,601)
U.S. Federal [Abstract]
Current			(41)	513	(460)
Deferred			61,205	34,980	(48,843)
Federal Income Tax Expense (Benefit), Continuing Operations			61,164	35,493	(49,303)
U.S. State [Abstract]
Current			5,498	3,793	1,560
Deferred			4,093	2,802	4,424
State and Local Income Tax Expense (Benefit), Continuing Operations			9,591	6,595	5,984
Foreign [Abstract]
Current			465	126	(511)
Foreign Income Tax Expense (Benefit), Continuing Operations			465	126	(511)
Consolidated [Abstract]
Current			5,922	4,432	589
Deferred			65,298	37,782	(44,419)
Total Provision (benefit) for taxes on income			$ 71,220	$ 42,214	$ (43,830)
Income Taxes [Abstract]
Effective income tax rate			21.00%	21.00%	21.00%
Tax refund amount					$ 119,500	$ 70,400
Income tax receivable				$ 70,400
State and local taxes, net of federal benefit			2.60%	3.10%	(1.70%)
United States [Member]
Earnings (loss) before taxes on income [Abstract]
Earnings (loss) before taxes on income			$ 293,011	$ 164,590	$ (290,181)
Foreign [Member]
Earnings (loss) before taxes on income [Abstract]
Earnings (loss) before taxes on income			$ 1,114	$ 385	$ (420)
Louisiana [Member]
Income Taxes [Abstract]
Effective income tax rate	8.00%	7.50%
State and local taxes, net of federal benefit	7.50%	6.30%
One-time deferred tax provision	$ 5,700

XML

Taxes on Income, Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Company's provision for taxes on income varied from the statutory federal income tax rate [Abstract]
United States income tax statutory rate	21.00%	21.00%	21.00%
State and local taxes, net of federal benefit	2.60%	3.10%	(1.70%)
Other - net	0.60%	1.50%	(4.20%)
Effective income tax rate	24.20%	25.60%	15.10%

XML

Taxes on Income, Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets [Abstract]
Allowance for doubtful accounts		$ 1,549	$ 1,556
Inventory		10,500	11,679
Insurance accruals		6,077	4,856
Deferred compensation		11,441	7,703
Unrealized gain on defined benefit plans		(9,982)	(5,532)
Goodwill and other intangibles		39,719	52,847
Operating loss carryforwards		52,082	79,699
Retirement benefits		3,548	5,472
Other		13,467	9,962
Deferred tax assets, gross		128,401	168,242
Valuation allowances		(22,073)	(19,960)
Deferred tax assets, net of valuation allowance		106,328	148,282
Deferred tax liabilities [Abstract]
Property		(695,233)	(671,830)
Deferred state taxes		(90,457)	(87,445)
Other		(17,195)	(14,891)
Deferred tax liabilities		(802,885)	(774,166)
Net deferred tax liabilities		(696,557)	(625,884)
Operating Loss Carryforward [Abstract]
Federal operating loss deferred tax assets		19,800	47,900
Deferred Tax Assets, State Taxes		27,200	26,600
Valuation allowance for state deferred tax assets		17,000	$ 14,800
Unrecognized tax benefits including interest and penalties		800
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		$ 700
Maximum [Member]
Operating Loss Carryforward [Abstract]
Expiration dates, operating loss carryforwards		Dec. 31, 2043
Minimum [Member]
Operating Loss Carryforward [Abstract]
Expiration dates, operating loss carryforwards		Dec. 31, 2037
Canada [Member]
Operating Loss Carryforward [Abstract]
Operating loss carryforwards		$ 5,100
Expiration dates, operating loss carryforwards		Dec. 31, 2030
Internal Revenue Service (IRS) [Member]
Open Tax Year [Abstract]
Years open to audit under the statute of limitations	2013 2014 2015 2016 2017 2018 2019 2020
State and Local Jurisdiction [Member]
Open Tax Year [Abstract]
Years open to audit under the statute of limitations	2017 2018 2019 2020 2021 2022

XML

Taxes on Income, Reconciliation of Liability for Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 662	$ 737	$ 783
Additions based on tax positions related to the current year	0	13	13
Additions for tax positions of prior years	0	66	281
Reductions for tax positions of prior years	(14)	(154)	(340)
Balance at end of year	648	662	$ 737
Accrued liabilities for payment of interest and penalties	$ 200	$ 200

XML

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net Income (Loss) Attributable to Parent [Abstract]
Net earnings (loss) attributable to Kirby	$ 222,935	$ 122,291	$ (246,954)
Undistributed earnings allocated to restricted shares	(62)	(33)	0
Earnings (loss) available to Kirby common stockholders - basic	222,873	122,258	(246,954)
Undistributed earnings allocated to restricted shares	62	33	0
Undistributed earnings allocated to restricted shares	(62)	(33)	0
Earnings (loss) available to Kirby common stockholders - diluted	$ 222,873	$ 122,258	$ (246,954)
Shares outstanding [Abstract]
Weighted average common stock issued and outstanding (in shares)	59,548,000	60,055,000	60,099,000
Weighted average unvested restricted stock (in shares)	(17,000)	(17,000)	(46,000)
Weighted Average Number of Shares Outstanding, Basic (in Shares)	59,531,000	60,038,000	60,053,000
Dilutive effect of stock options and restricted stock units (in shares)	326,000	291,000	0
Weighted Average Number of Shares Outstanding, Diluted (in Shares)	59,857,000	60,329,000	60,053,000
Net earnings (loss) per share basic attributable to Kirby common stockholders:
Basic (in dollars per share)	$ 3.74	$ 2.04	$ (4.11)
Net earnings (loss) per share diluted attributable to Kirby common stockholders:
Diluted (in dollars per share)	$ 3.72	$ 2.03	$ (4.11)
Antidilutive securities excluded from computation of earnings per share (in shares)	33,000	381,000	567,000
Restricted Stock Units (RSUs) [Member]
Net earnings (loss) per share diluted attributable to Kirby common stockholders:
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0	7,000

XML

Schedule of Inventories, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Inventory, Net [Abstract]
Inventory, Finished Goods, Gross	$ 351,050	$ 358,702
Inventory, Work in Process, Gross	103,339	103,146
Inventories - net	$ 454,389	$ 461,848

XML

Retirement Plans, Information About Plan Assets and Asset Allocation (Details) - USD ($)		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
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
Fair Value, Inputs, Level 3 [Member]
Information about Plan Assets [Abstract]
Fair value of plan assets		$ 0		$ 0
Cash and Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Information about Plan Assets [Abstract]
Fair value of plan assets				4,800
Pension Plan [Member]
Information about Plan Assets [Abstract]
Pension contributions		8,174,000		906,000
Fair value of plan assets		$ 375,917,000		$ 341,061,000		$ 430,821,000
Expected long-term rate of return on plan assets		6.75%		6.75%		6.75%
Contribution percentage to defined contribution plan		115.00%
Discount rate		5.50%	[1]	3.00%
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%
Pension Plan [Member] | Maximum [Member]
Information about Plan Assets [Abstract]
Discount rate				3.10%	[1]	2.90%
Pension Plan [Member] | U.S. Equity Securities [Member]
Asset Allocation Among Asset Categories [Abstract]
Asset allocations		51.00%		50.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		50.00%
Pension Plan [Member] | U.S. Equity Securities [Member] | Minimum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		45.00%
Pension Plan [Member] | U.S. Equity Securities [Member] | Maximum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		55.00%
Pension Plan [Member] | International Equity Securities [Member]
Asset Allocation Among Asset Categories [Abstract]
Asset allocations		20.00%		20.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		20.00%
Pension Plan [Member] | International Equity Securities [Member] | Minimum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		12.00%
Pension Plan [Member] | International Equity Securities [Member] | Maximum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		28.00%
Pension Plan [Member] | Debt Securities [Member]
Asset Allocation Among Asset Categories [Abstract]
Asset allocations		29.00%		30.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		30.00%
Pension Plan [Member] | Debt Securities [Member] | Minimum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		20.00%
Pension Plan [Member] | Debt Securities [Member] | Maximum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		40.00%
Pension Plan [Member] | Cash and Cash Equivalents [Member]
Asset Allocation Among Asset Categories [Abstract]
Asset allocations		0.00%		0.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Minimum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Pension Plan [Member] | Cash and Cash Equivalents [Member] | Maximum [Member]
Asset Allocation Among Asset Categories [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
SERP [Member]
Information about Plan Assets [Abstract]
Pension contributions		$ 153,000		$ 155,000
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]	5.50%		3.00%		2.80%
Other Postretirement Benefits [Member]
Information about Plan Assets [Abstract]
Pension contributions		$ 104,000		$ 109,000
Fair value of plan assets		$ 0		$ 0		$ 0
Pension plan defined benefit plan cost increase limit percentage		4.00%
Discount rate		5.50%		3.00%		2.80%
Seafarers Pension Trust [Member]
Information about Plan Assets [Abstract]
Pension contributions		$ 400,000		$ 500,000
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		600,000		$ 700,000
Contribution percentage to defined contribution plan				107.00%
Higman Pension Plan [Member]
Information about Plan Assets [Abstract]
Pension contributions		$ 8,200,000		$ 900,000		$ 500
Discount rate				3.10%

[1] The 2023 discount rate for benefit cost is 5.5% for both the Kirby Pension Plan and the Higman Pension Plan. The 2022 discount rate for benefit cost is 3.0% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan.

XML

Retirement Plans, Schedule of Change in Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 339,509	$ 495,272
Service cost	3,695	6,538	$ 7,961
Interest cost	18,356	14,779	14,239
Actuarial (gain) loss	13,241	(158,816)
Gross benefits paid	(32,052)	(12,665)
Settlements	0	(5,599)
Benefit obligation at end of year	342,749	339,509	495,272
Accumulated benefit obligation at end of year	326,987	325,274
SERP [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	833	1,033
Service cost	0	0	0
Interest cost	43	29	31
Actuarial (gain) loss	91	(74)
Gross benefits paid	(153)	(155)
Settlements	0	0
Benefit obligation at end of year	814	833	1,033
Accumulated benefit obligation at end of year	814	833
Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	432	582
Service cost	0	0
Interest cost	22	17	17
Actuarial (gain) loss	65	(58)
Gross benefits paid	(104)	(109)
Settlements	0	0
Benefit obligation at end of year	415	432	$ 582
Accumulated benefit obligation at end of year	$ 415	$ 432

XML

Retirement Plans, Weighted-Average Assumption Used to Determine Benefit Obligation (Details)		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Pension Plan [Member]
Weighted-average assumption used to determine benefit obligation at end of year [Abstract]
Discount rate		5.10%	5.50%	[1]
Health care cost trend rate [Abstract]
Initial rate		0.00%	0.00%
Ultimate rate		0.00%	0.00%
Pension Plan [Member] | Minimum [Member]
Weighted-average assumption used to determine benefit obligation at end of year [Abstract]
Discount rate	[1]	5.10%
Pension Plan [Member] | Maximum [Member]
Weighted-average assumption used to determine benefit obligation at end of year [Abstract]
Discount rate	[1]	5.20%
SERP [Member]
Weighted-average assumption used to determine benefit obligation at end of year [Abstract]
Discount rate	[1]	5.10%	5.50%
Rate of compensation increase		0.00%	0.00%
Health care cost trend rate [Abstract]
Initial rate		0.00%	0.00%
Ultimate rate		0.00%	0.00%
Other Postretirement Benefits [Member]
Weighted-average assumption used to determine benefit obligation at end of year [Abstract]
Discount rate	[1]	5.10%	5.50%
Rate of compensation increase		0.00%	0.00%
Health care cost trend rate [Abstract]
Initial rate		6.25%	6.50%
Ultimate rate		5.00%	5.00%
Years to ultimate		2029	2029
Higman Pension Plan [Member]
Weighted-average assumption used to determine benefit obligation at end of year [Abstract]
Discount rate		5.20%	5.50%

[1] The 2023 discount rate was 5.1% for the Kirby Pension Plan and 5.2% for the Higman Pension Plan. The 2022 discount rate was 5.5% for both the Kirby Pension Plan and the Higman Pension Plan.

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Retirement Plans, Summary of Change in Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pension Plan [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 341,061	$ 430,821
Actual return on plan assets	58,734	(72,402)
Employer contribution	8,174	906
Gross benefits paid	(32,052)	(12,665)
Settlements	0	(5,599)
Fair value of plan assets at end of year	375,917	341,061
SERP [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contribution	153	155
Gross benefits paid	(153)	(155)
Settlements	0	0
Fair value of plan assets at end of year	0	0
Other Postretirement Benefits [Member]
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contribution	104	109
Gross benefits paid	(104)	(109)
Settlements	0	0
Fair value of plan assets at end of year	$ 0	$ 0

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Retirement Plans, Summary of Funded Status at End of Year (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Plan [Member]
Funded status at end of year [Abstract]
Fair value of plan assets	$ 375,917	$ 341,061	$ 430,821
Benefit obligations	(342,749)	(339,509)	(495,272)
Funded status and amount recognized at end of year	33,168	1,552
SERP [Member]
Funded status at end of year [Abstract]
Fair value of plan assets	0	0	0
Benefit obligations	(814)	(833)	(1,033)
Funded status and amount recognized at end of year	(814)	(833)
Other Postretirement Benefits [Member]
Funded status at end of year [Abstract]
Fair value of plan assets	0	0	0
Benefit obligations	(415)	(432)	$ (582)
Funded status and amount recognized at end of year	$ (415)	$ (432)

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Retirement Plans, Amounts Recognized in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Pension Plan [Member]
Amounts recognized in the consolidated balance sheets [Abstract]
Noncurrent asset	$ 42,698	$ 18,695
Current liability	0	0
Long-term liability	(9,530)	(17,143)
SERP [Member]
Amounts recognized in the consolidated balance sheets [Abstract]
Noncurrent asset	0	0
Current liability	(106)	(106)
Long-term liability	(708)	(727)
Other Postretirement Benefits [Member]
Amounts recognized in the consolidated balance sheets [Abstract]
Noncurrent asset	0	0
Current liability	(46)	(49)
Long-term liability	$ (369)	$ (383)

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Retirement Plans, Amounts Recognized in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Pension Plan [Member]
Amounts recognized in accumulated other comprehensive income [Abstract]
Net actuarial (gain) loss	$ (48,033)	$ (25,449)
Prior service cost (credit)	0	0
Accumulated other compensation income	(48,033)	(25,449)
SERP [Member]
Amounts recognized in accumulated other comprehensive income [Abstract]
Net actuarial (gain) loss	391	324
Prior service cost (credit)	0	0
Accumulated other compensation income	391	324
Other Postretirement Benefits [Member]
Amounts recognized in accumulated other comprehensive income [Abstract]
Net actuarial (gain) loss	(1,890)	(2,299)
Prior service cost (credit)	0	0
Accumulated other compensation income	$ (1,890)	$ (2,299)

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Retirement Plans, Expected Employer Contribution and Benefit Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Pension Plan [Member]
Expected employer contributions [Abstract]
First year	$ 1,770	$ 8,374
Expected benefit payments (gross) [Abstract]
Year one	16,696	16,312
Year two	17,513	16,899
Year three	18,169	17,808
Year four	19,096	18,650
Year five	19,860	19,707
Next five years	108,717	110,417
SERP [Member]
Expected employer contributions [Abstract]
First year	0	0
Expected benefit payments (gross) [Abstract]
Year one	108	108
Year two	103	104
Year three	98	99
Year four	93	94
Year five	88	90
Next five years	337	359
Other Postretirement Benefits [Member]
Expected employer contributions [Abstract]
First year	0	0
Expected benefit payments (gross) [Abstract]
Year one	47	50
Year two	46	49
Year three	44	47
Year four	43	45
Year five	41	43
Next five years	$ 167	$ 176

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Retirement Plans, Components of Net Periodic Benefit Cost, Pension Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Components of net periodic benefit cost [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax
Other changes in plan assets and benefit obligations recognized in other comprehensive income [Abstract]
Recognition of actuarial loss	$ (22,438)	$ (58,147)	$ (44,491)
Pension Plan [Member]
Components of net periodic benefit cost [Abstract]
Service cost	3,695	6,538	7,961
Interest cost	18,356	14,779	14,239
Expected return on plan assets	(22,910)	(28,399)	(26,244)
Amortization of actuarial loss	0	34	4,193
Net periodic benefit cost	(859)	(7,048)	(149)
Other changes in plan assets and benefit obligations recognized in other comprehensive income [Abstract]
Current year actuarial (gain) loss	(22,583)	(58,015)	(44,583)
Recognition of actuarial loss	0	(34)	(4,193)
Total recognized in other comprehensive income	(22,583)	(58,049)	(48,776)
Total recognized in net periodic benefit cost and other comprehensive income	(23,442)	(65,097)	(48,627)
SERP [Member]
Components of net periodic benefit cost [Abstract]
Service cost	0	0	0
Interest cost	43	29	31
Expected return on plan assets	0	0	0
Amortization of actuarial loss	23	30	40
Net periodic benefit cost	66	59	71
Other changes in plan assets and benefit obligations recognized in other comprehensive income [Abstract]
Current year actuarial (gain) loss	91	(74)	(12)
Recognition of actuarial loss	(23)	(30)	(40)
Total recognized in other comprehensive income	68	(104)	(52)
Total recognized in net periodic benefit cost and other comprehensive income	$ 134	$ (45)	$ 19

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Retirement Plans, Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost, Pension Benefits (Details)		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Pension Benefits [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate		5.50%	[1]	3.00%
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%
Pension Benefits [Member] | Minimum [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate				3.00%	[1]	2.80%
SERP [Member]
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate	[1]	5.50%		3.00%		2.80%
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				3.10%

[1] The 2023 discount rate for benefit cost is 5.5% for both the Kirby Pension Plan and the Higman Pension Plan. The 2022 discount rate for benefit cost is 3.0% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan.

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Retirement Plans, Components of Net Periodic Benefit Cost, Other Postretirement Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Recognition of actuarial gain	$ (22,438)	$ (58,147)	$ (44,491)
Other Postretirement Benefits [Member]
Components of net periodic benefit cost [Abstract]
Interest cost	22	17	17
Amortization of actuarial gain	(344)	(394)	(451)
Net periodic benefit cost	(322)	(377)	(434)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Current year actuarial loss (gain)	65	(58)	104
Recognition of actuarial gain	344	394	451
Total recognized in other comprehensive income	409	336	555
Total recognized in net periodic benefit cost and other comprehensive income	$ 87	$ (41)	$ 121

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Retirement Plans, Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost, Other Postretirement Benefits (Details) - Other Postretirement Benefits [Member]	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Weighted average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate	5.50%	3.00%	2.80%
Health care cost trend rate [Abstract]
Initial rate	6.50%	6.25%	6.50%
Ultimate rate	5.00%	5.00%	5.00%
Years to ultimate	2029	2027	2025

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Retirement Plans, Multiemployer Pension Plan and Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Plans [Abstract]
Aggregate contributions to the plans	$ 26.9	$ 27.9	$ 25.9
Seafarers Pension Trust [Member]
Retirement Plans [Abstract]
Pension contributions	0.4	$ 0.5
Contribution percentage to defined contribution plan		100.00%
Maximum contribution limit		5.00%
CPF [Member]
Retirement Plans [Abstract]
Pension contributions	$ 0.6	$ 0.7
Contribution percentage to defined contribution plan		107.00%

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Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax [Abstract]
Amortization of net actuarial (gain) loss, Gross Amount	$ (321)	$ (330)	$ 3,782
Amortization of net actuarial (gain) loss, Income Tax (Provision) Benefit	78	81	(952)
Amortization of net actuarial (gain) loss, Net Amount	(243)	(249)	2,830
Actuarial gain , Gross Amount	22,438	58,147	44,491
Actuarial gain , Income Tax (Provision) Benefit	(5,467)	(14,030)	(10,774)
Actuarial gain , Net Amount	16,971	44,117	33,717
Foreign currency translation, Gross Amount	1,425	(1,049)	(1,061)
Foreign currency translation, Income Tax (Provision) Benefit	0	0	0
Foreign currency translation, Net Amount	1,425	(1,049)	(1,061)
Total other comprehensive income (loss), Gross Amount	23,542	56,768	47,212
Total other comprehensive income (loss), Income Tax (Provision) Benefit	(5,389)	(13,949)	(11,726)
Total other comprehensive income , net of taxes	$ 18,153	$ 42,819	$ 35,486

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Contingencies and Commitments (Details)	12 Months Ended
	Dec. 31, 2023 Bargeslip Company Spill
Portland Harbor Superfund Site [Member]
Loss Contingencies [Line Items]
Number of other companies also named as Potentially Responsible Parties ("PRPs") | Company	250
Number of spills | Spill	4
SBA Shipyard Site [Member]
Loss Contingencies [Line Items]
Number of barge slips | Bargeslip	3

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Contingencies and Commitments, Certain Significant Risks and Uncertainties (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Issued guaranties	$ 26.7
Maximum [Member]
Loss Contingencies [Line Items]
Guarantor obligations, expiration period	2 years
Performance Bonds [Member]
Loss Contingencies [Line Items]
Issued guaranties	$ 14.6
Letters Of Credit [Member]
Loss Contingencies [Line Items]
Issued guaranties	$ 12.1

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Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
ABS [Member]
Related Party [Abstract]
Related party expenses	$ 1.5	$ 1.3	$ 1.6
UK Protection & Indemnity Association [Member]
Related Party [Abstract]
Related party expenses	3.6	3.4	3.2
Signal Member
Related Party [Abstract]
Related party expenses	0.7	0.5	0.6
Strasburger & Price, LLP Member
Related Party [Abstract]
Legal services	0.9	1.0	2.9
W. Sean O'Neil Attorney Member
Related Party [Abstract]
Legal services	0.1	$ 0.1	$ 0.1
Mansfield Service Partners Member
Related Party [Abstract]
Related party expenses	$ 29.4