Nature of Operations and Significant Accounting Policies	12 Months Ended
Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Significant Accounting Policies	Nature of Operations and Significant Accounting Policies Business CSX Corporation together with its subsidiaries ("CSX" or the “Company”), based in Jacksonville, Florida, is one of the nation's leading transportation companies. The Company provides rail-based transportation services including traditional rail service, the transport of intermodal containers and trailers, as well as other transportation services such as rail-to-truck transfers and bulk commodity operations. CSX Transportation, Inc. CSX’s principal operating subsidiary, CSX Transportation, Inc. (“CSXT”), provides an important link to the transportation supply chain through its approximately 20,000 route mile rail network and serves major population centers in 26 states east of the Mississippi River, the District of Columbia and the Canadian provinces of Ontario and Quebec. It has access to over 70 ocean, river and lake port terminals along the Atlantic and Gulf Coasts, the Mississippi River, the Great Lakes and the St. Lawrence Seaway. The Company’s intermodal business links customers to railroads via trucks and terminals. CSXT also serves thousands of production and distribution facilities through track connections to more than 240 short-line and regional railroads. On June 1, 2022, CSX completed its acquisition of Pan Am Systems, Inc. (“Pan Am”), which is the parent company of Pan Am Railways, Inc. This acquisition expands CSXT’s reach in the Northeastern United States. For further details, refer to Note 17, Business Combinations. CSXT is also responsible for the Company's real estate sales, leasing, acquisition and management and development activities. Substantially all of these activities are focused on supporting railroad operations. Other Entities In addition to CSXT, the Company’s subsidiaries include Quality Carriers, Inc. ("Quality Carriers"), CSX Intermodal Terminals, Inc. (“CSX Intermodal Terminals”), Total Distribution Services, Inc. (“TDSI”), TRANSFLO Terminal Services, Inc. (“TRANSFLO”), CSX Technology, Inc. (“CSX Technology”) and other subsidiaries. Quality Carriers is the largest provider of bulk liquid chemicals truck transportation in North America. CSX Intermodal Terminals owns and operates a system of intermodal terminals, predominantly in the eastern United States, and also provides drayage services (the pickup and delivery of intermodal shipments) for certain customers. TDSI serves the automotive industry with distribution centers and storage locations. TRANSFLO connects non-rail served customers to the many benefits of rail by transferring products from rail to trucks. The biggest TRANSFLO markets are chemicals and agriculture, which include shipments of plastics and ethanol. CSX Technology and other subsidiaries provide support services for the Company. NOTE 1. Nature of Operations and Significant Accounting Policies, continued Lines of Business During 2024, the Company's services generated $14.5 billion of revenue and served four primary lines of business: merchandise, intermodal, coal and trucking. •The merchandise business shipped 2.6 million carloads (42% of volume) and generated $8.9 billion in revenue (61% of revenue) in 2024. The Company’s merchandise business is comprised of shipments in the following diverse markets: chemicals, agricultural and food products, minerals, automotive, forest products, metals and equipment, and fertilizers. •The intermodal business shipped 2.9 million units (46% of volume) and generated $2.0 billion in revenue (14% of revenue) in 2024. The intermodal business combines the superior economics of rail transportation with the flexibility of trucks and offers a cost and environmental advantage over long-haul trucking. Through a network of approximately 30 terminals, the intermodal business serves all major markets east of the Mississippi River and transports mainly manufactured consumer goods in containers, providing customers with truck-like service for longer shipments. •The coal business shipped 736 thousand carloads (12% of volume) and generated $2.2 billion in revenue (15% of revenue) in 2024. The Company transports domestic coal, coke and iron ore to electricity-generating power plants, steel manufacturers and industrial plants as well as export coal to deep-water port facilities. Most of the export coal the Company transports is used for steelmaking, while the majority of domestic coal the Company ships is used for electricity generation. •The trucking business generated $844 million, or 6%, of revenue in 2024. Trucking revenue includes revenue from the operations of Quality Carriers. Other revenue accounted for 4% of the Company’s total revenue in 2024. This category includes revenue from regional subsidiary railroads and incidental charges, including intermodal storage and equipment usage, demurrage and switching. Revenue from regional subsidiary railroads includes shipments by railroads that the Company does not directly operate. Intermodal storage represents charges for customer storage of containers at an intermodal terminal, ramp facility or offsite location beyond a specified period of time. Demurrage represents charges assessed when freight cars are held by a customer beyond a specified period of time. Switching represents charges assessed when a railroad switches cars for a customer or another railroad. Segments The Company has two operating segments: rail and trucking. Although the Company provides a breakdown of revenue by line of business, the overall financial and operational performance of the railroad is analyzed as one operating segment due to the integrated nature of the rail network. The trucking segment is not material for separate disclosure. See Note 18, Segment Reporting and Significant Expenses, for additional information on the Company's segments. Employees The Company's number of employees was more than 23,500 as of December 2024, which includes approximately 17,500 union employees. Most of the Company’s employees provide or support transportation services. NOTE 1. Nature of Operations and Significant Accounting Policies, continued Basis of Presentation In the opinion of management, the accompanying consolidated financial statements contain all normal, recurring adjustments necessary to fairly present the financial position of CSX and its subsidiaries at December 31, 2024 and December 31, 2023, and the consolidated statements of income, comprehensive income, cash flows and changes in shareholders’ equity for the years ended 2024, 2023 and 2022. In addition, management has evaluated and disclosed all material events occurring subsequent to the date of the financial statements up to the date this annual report is filed on Form 10-K. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires that management make estimates in reporting the amounts of certain assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of certain revenues and expenses during the reporting period. Actual results may differ from those estimates. Critical accounting estimates using management judgment are made for the following areas: •personal injury and environmental reserves (see Note 5, Casualty, Environmental and Other Reserves); •pension plan accounting (see Note 9, Employee Benefit Plans); and •depreciation policies for assets under the group-life method (see Note 6, Properties) Fiscal Year The Company's fiscal periods are based upon the calendar year. Except as otherwise specified, references to full years indicate CSX’s fiscal years ended on December 31, 2024, December 31, 2023, and December 31, 2022. Principles of Consolidation The consolidated financial statements include results of operations of CSX and subsidiaries over which CSX has majority ownership or financial control. All significant intercompany accounts and transactions have been eliminated. Most investments in companies that were not majority-owned were carried at cost (if less than 20% owned and the Company has no significant influence) or were accounted for under the equity method (if the Company has significant influence but does not have control). These investments are reported within Investment in Affiliates and Other Companies on the consolidated balance sheets. NOTE 1. Nature of Operations and Significant Accounting Policies, continued Cash and Cash Equivalents On a daily basis, cash in excess of current operating requirements is invested in various highly liquid investments having a typical maturity date of three months or less at the date of acquisition. These investments are carried at cost, which approximates market value, and are classified as cash equivalents. Investments Investments in instruments with original maturities greater than three months that will mature in less than one year are classified as short-term investments. Investments with original maturities of one year or greater are initially classified within other long-term assets, and the classification is re-evaluated at each balance sheet date. Materials and Supplies Materials and supplies in the consolidated balance sheets are carried at average cost and consist primarily of parts used in the repair and maintenance of track structure, equipment, and CSXT’s freight car and locomotive fleets, as well as fuel. New Accounting Pronouncements In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2023-07, Improvements to Reportable Segment Disclosures. This standard update requires additional interim and annual disclosures about a reportable segment’s expenses, even for companies with only one reportable segment. The Company adopted this guidance for this 2024 annual report filed on Form 10-K and the standard update did not impact the Company's results of operations or financial position as the update only impacts disclosures. See Note 18, Segment Reporting and Significant Expenses. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. This standard update requires additional interim and annual disclosures about a company’s income taxes, including more detailed information around the annual rate reconciliation and income taxes paid. The Company is required to adopt the guidance for its 2025 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position. In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses. This standard update requires additional disclosures about certain expenses in commonly presented expense captions. The Company is required to adopt the guidance for its 2027 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position. Revision of Prior Period Financial Statements During second quarter 2024, CSX completed a review of the accounting treatment for engineering scrap and certain engineering support labor and identified misstatements between the balance sheet and operating expense in previously issued financial statements. The Company determined the impacts of these misstatement were immaterial to the financial statements for all prior periods identified. For comparative purposes, the Company has made corrections to the consolidated financial statements and applicable notes for the prior periods presented in this Form 10-K. See Note 20, Revision of Prior Period Financial Statements, for additional information and quantification of prior period restatement impacts.

CSX Corporation together with its subsidiaries ("CSX" or the “Company”), based in Jacksonville, Florida, is one of the nation's leading transportation companies. The Company provides rail-based transportation services including traditional rail service, the transport of intermodal containers and trailers, as well as other transportation services such as rail-to-truck transfers and bulk commodity operations.

CSX’s principal operating subsidiary, CSX Transportation, Inc. (“CSXT”), provides an important link to the transportation supply chain through its approximately 20,000 route mile rail network and serves major population centers in 26 states east of the Mississippi River, the District of Columbia and the Canadian provinces of Ontario and Quebec. It has access to over 70 ocean, river and lake port terminals along the Atlantic and Gulf Coasts, the Mississippi River, the Great Lakes and the St. Lawrence Seaway. The Company’s intermodal business links customers to railroads via trucks and terminals. CSXT also serves thousands of production and distribution facilities through track connections to more than 240 short-line and regional railroads. On June 1, 2022, CSX completed its acquisition of Pan Am Systems, Inc. (“Pan Am”), which is the parent company of Pan Am Railways, Inc. This acquisition expands CSXT’s reach in the Northeastern United States. For further details, refer to Note 17, Business Combinations.

In addition to CSXT, the Company’s subsidiaries include Quality Carriers, Inc. ("Quality Carriers"), CSX Intermodal Terminals, Inc. (“CSX Intermodal Terminals”), Total Distribution Services, Inc. (“TDSI”), TRANSFLO Terminal Services, Inc. (“TRANSFLO”), CSX Technology, Inc. (“CSX Technology”) and other subsidiaries. Quality Carriers is the largest provider of bulk liquid chemicals truck transportation in North America. CSX Intermodal Terminals owns and operates a system of intermodal terminals, predominantly in the eastern United States, and also provides drayage services (the pickup and delivery of intermodal shipments) for certain customers. TDSI serves the automotive industry with distribution centers and storage locations. TRANSFLO connects non-rail served customers to the many benefits of rail by transferring products from rail to trucks. The biggest TRANSFLO markets are chemicals and agriculture, which include shipments of plastics and ethanol. CSX Technology and other subsidiaries provide support services for the Company.

•The merchandise business shipped 2.6 million carloads (42% of volume) and generated $8.9 billion in revenue (61% of revenue) in 2024. The Company’s merchandise business is comprised of shipments in the following diverse markets: chemicals, agricultural and food products, minerals, automotive, forest products, metals and equipment, and fertilizers.

•The intermodal business shipped 2.9 million units (46% of volume) and generated $2.0 billion in revenue (14% of revenue) in 2024. The intermodal business combines the superior economics of rail transportation with the flexibility of trucks and offers a cost and environmental advantage over long-haul trucking. Through a network of approximately 30 terminals, the intermodal business serves all major markets east of the Mississippi River and transports mainly manufactured consumer goods in containers, providing customers with truck-like service for longer shipments.

•The coal business shipped 736 thousand carloads (12% of volume) and generated $2.2 billion in revenue (15% of revenue) in 2024. The Company transports domestic coal, coke and iron ore to electricity-generating power plants, steel manufacturers and industrial plants as well as export coal to deep-water port facilities. Most of the export coal the Company transports is used for steelmaking, while the majority of domestic coal the Company ships is used for electricity generation.

Other revenue accounted for 4% of the Company’s total revenue in 2024. This category includes revenue from regional subsidiary railroads and incidental charges, including intermodal storage and equipment usage, demurrage and switching. Revenue from regional subsidiary railroads includes shipments by railroads that the Company does not directly operate. Intermodal storage represents charges for customer storage of containers at an intermodal terminal, ramp facility or offsite location beyond a specified period of time. Demurrage represents charges assessed when freight cars are held by a customer beyond a specified period of time. Switching represents charges assessed when a railroad switches cars for a customer or another railroad.

The Company has two operating segments: rail and trucking. Although the Company provides a breakdown of revenue by line of business, the overall financial and operational performance of the railroad is analyzed as one operating segment due to the integrated nature of the rail network. The trucking segment is not material for separate disclosure. See Note 18, Segment Reporting and Significant Expenses, for additional information on the Company's segments.

In the opinion of management, the accompanying consolidated financial statements contain all normal, recurring adjustments necessary to fairly present the financial position of CSX and its subsidiaries at December 31, 2024 and December 31, 2023, and the consolidated statements of income, comprehensive income, cash flows and changes in shareholders’ equity for the years ended 2024, 2023 and 2022. In addition, management has evaluated and disclosed all material events occurring subsequent to the date of the financial statements up to the date this annual report is filed on Form 10-K.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires that management make estimates in reporting the amounts of certain assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of certain revenues and expenses during the reporting period. Actual results may differ from those estimates. Critical accounting estimates using management judgment are made for the following areas:

The Company's fiscal periods are based upon the calendar year. Except as otherwise specified, references to full years indicate CSX’s fiscal years ended on December 31, 2024, December 31, 2023, and December 31, 2022.

The consolidated financial statements include results of operations of CSX and subsidiaries over which CSX has majority ownership or financial control. All significant intercompany accounts and transactions have been eliminated. Most investments in companies that were not majority-owned were carried at cost (if less than 20% owned and the Company has no significant influence) or were accounted for under the equity method (if the Company has significant influence but does not have control). These investments are reported within Investment in Affiliates and Other Companies on the consolidated balance sheets.

On a daily basis, cash in excess of current operating requirements is invested in various highly liquid investments having a typical maturity date of three months or less at the date of acquisition. These investments are carried at cost, which approximates market value, and are classified as cash equivalents.

Investments in instruments with original maturities greater than three months that will mature in less than one year are classified as short-term investments. Investments with original maturities of one year or greater are initially classified within other long-term assets, and the classification is re-evaluated at each balance sheet date.

Materials and supplies in the consolidated balance sheets are carried at average cost and consist primarily of parts used in the repair and maintenance of track structure, equipment, and CSXT’s freight car and locomotive fleets, as well as fuel.

In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2023-07, Improvements to Reportable Segment Disclosures. This standard update requires additional interim and annual disclosures about a reportable segment’s expenses, even for companies with only one reportable segment. The Company adopted this guidance for this 2024 annual report filed on Form 10-K and the standard update did not impact the Company's results of operations or financial position as the update only impacts disclosures. See Note 18, Segment Reporting and Significant Expenses.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. This standard update requires additional interim and annual disclosures about a company’s income taxes, including more detailed information around the annual rate reconciliation and income taxes paid. The Company is required to adopt the guidance for its 2025 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position.

In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses. This standard update requires additional disclosures about certain expenses in commonly presented expense captions. The Company is required to adopt the guidance for its 2027 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position.

During second quarter 2024, CSX completed a review of the accounting treatment for engineering scrap and certain engineering support labor and identified misstatements between the balance sheet and operating expense in previously issued financial statements. The Company determined the impacts of these misstatement were immaterial to the financial statements for all prior periods identified. For comparative purposes, the Company has made corrections to the consolidated financial statements and applicable notes for the prior periods presented in this Form 10-K. See Note 20, Revision of Prior Period Financial Statements, for additional information and quantification of prior period restatement impacts.