Note A - Summary of Financial Statement Preparation and Significant Accounting Policies	3 Months Ended
Mar. 31, 2024
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]	NOTE A—SUMMARY OF FINANCIAL STATEMENT PREPARATION AND SIGNIFICANT ACCOUNTING POLICIES Nature of Operations ATSG is a holding company whose subsidiaries lease aircraft and provide contracted airline operations as well as other support services mainly to the air transportation, e-commerce and package delivery industries. The Company's leasing subsidiary, Cargo Aircraft Management, Inc. (“CAM”), leases aircraft to each of the Company's airlines as well as to non-affiliated airlines and other lessees. The Company's airlines, ABX Air, Inc. (“ABX”), Air Transport International, Inc. (“ATI”) and Omni Air International, LLC ("OAI") each have the authority, through their separate U.S. Department of Transportation ("DOT") and Federal Aviation Administration ("FAA") certificates, to transport cargo worldwide. The Company provides a combination of aircraft, crews, maintenance and insurance services for its customers' transportation network through crew, maintenance and insurance ("CMI") agreements and aircraft, crew, maintenance and insurance ("ACMI") agreements and through charter contracts in which aircraft fuel is also included. The Company's subsidiary, LGSTX Services, Inc. ("LGSTX") provides for the management of aircraft ground services. In addition to its aircraft leasing and airline services, the Company offers a range of complementary services to delivery companies, freight forwarders, airlines and government customers. These include aircraft maintenance and modification services, aircraft parts supply, equipment maintenance services and load transfer and package sorting services. Basis of Presentation The financial statements of the Company are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). The accompanying unaudited condensed interim consolidated financial statements are prepared in conformity with GAAP and such principles are applied on a basis consistent with the financial statements reflected in our 2023 Form 10-K. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations promulgated by the SEC related to interim financial statements. In the opinion of management, the accompanying financial statements contain all adjustments, including normal recurring adjustments, necessary for the fair presentation of the Company's results of operations and financial position for the periods presented. Due to seasonal fluctuations, among other factors common to the air cargo industry, the results of operations for the periods presented are not necessarily indicative of the results of operations to be expected for the entire year or any interim period. The preparation of consolidated financial statements requires management to make estimates and assumptions that affect amounts reported in the consolidated financial statements. The accounting estimates reflect the best judgment of the management, but actual results could differ materially from those estimates. The accompanying unaudited condensed consolidated financial statements include the accounts of ATSG and its wholly-owned subsidiaries. Inter-company balances and transactions are eliminated. Investments in affiliates in which the Company has significant influence but does not exercise control are accounted for using the equity method of accounting. Under the equity method, the Company's share of the non-consolidated affiliate's income or loss is recognized in the consolidated statement of earnings and cumulative post-acquisition changes in the investment are adjusted against the carrying amount of the investment. Accounting Standards Updates In November 2023, the FASB issued ASU No. 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures." This standard requires disclosure of significant segment expenses and other segment items by reportable segment. This ASU becomes effective for annual periods beginning in 2024 and interim periods in 2025. The Company is assessing the impact of this ASU and upon adoption expects that any impact would be limited to additional segment expense disclosures in the footnotes to its consolidated financial statements. In December 2023, the FASB issued ASU No. 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures." This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. This ASU becomes effective January 1, 2025. The Company is assessing the impact of this ASU and upon adoption expects to include certain additional disclosures in the footnotes to its consolidated financial statements.

Note A - Summary of Financial Statement Preparation and Significant Accounting Policies

3 Months Ended

Mar. 31, 2024

Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]

NOTE A—SUMMARY OF FINANCIAL STATEMENT PREPARATION AND SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations

ATSG is a holding company whose subsidiaries lease aircraft and provide contracted airline operations as well as other support services mainly to the air transportation, e-commerce and package delivery industries.

The Company's leasing subsidiary, Cargo Aircraft Management, Inc. (“CAM”), leases aircraft to each of the Company's airlines as well as to non-affiliated airlines and other lessees. The Company's airlines, ABX Air, Inc. (“ABX”), Air Transport International, Inc. (“ATI”) and Omni Air International, LLC ("OAI") each have the authority, through their separate U.S. Department of Transportation ("DOT") and Federal Aviation Administration ("FAA") certificates, to transport cargo worldwide. The Company provides a combination of aircraft, crews, maintenance and insurance services for its customers' transportation network through crew, maintenance and insurance ("CMI") agreements and aircraft, crew, maintenance and insurance ("ACMI") agreements and through charter contracts in which aircraft fuel is also included. The Company's subsidiary, LGSTX Services, Inc. ("LGSTX") provides for the management of aircraft ground services.

In addition to its aircraft leasing and airline services, the Company offers a range of complementary services to delivery companies, freight forwarders, airlines and government customers. These include aircraft maintenance and modification services, aircraft parts supply, equipment maintenance services and load transfer and package sorting services.

Basis of Presentation

The financial statements of the Company are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). The accompanying unaudited condensed interim consolidated financial statements are prepared in conformity with GAAP and such principles are applied on a basis consistent with the financial statements reflected in our 2023 Form 10-K. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations promulgated by the SEC related to interim financial statements. In the opinion of management, the accompanying financial statements contain all adjustments, including normal recurring adjustments, necessary for the fair presentation of the Company's results of operations and financial position for the periods presented. Due to seasonal fluctuations, among other factors common to the air cargo industry, the results of operations for the periods presented are not necessarily indicative of the results of operations to be expected for the entire year or any interim period. The preparation of consolidated financial statements requires management to make estimates and assumptions that affect amounts reported in the consolidated financial statements. The accounting estimates reflect the best judgment of the management, but actual results could differ materially from those estimates.

The accompanying unaudited condensed consolidated financial statements include the accounts of ATSG and its wholly-owned subsidiaries. Inter-company balances and transactions are eliminated. Investments in affiliates in which the Company has significant influence but does not exercise control are accounted for using the equity method of accounting. Under the equity method, the Company's share of the non-consolidated affiliate's income or loss is recognized in the consolidated statement of earnings and cumulative post-acquisition changes in the investment are adjusted against the carrying amount of the investment.

Accounting Standards Updates

In November 2023, the FASB issued ASU No. 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures." This standard requires disclosure of significant segment expenses and other segment items by reportable segment. This ASU becomes effective for annual periods beginning in 2024 and interim periods in 2025. The Company is assessing the impact of this ASU and upon adoption expects that any impact would be limited to additional segment expense disclosures in the footnotes to its consolidated financial statements.

In December 2023, the FASB issued ASU No. 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures." This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. This ASU becomes effective January 1, 2025. The Company is assessing the impact of this ASU and upon adoption expects to include certain additional disclosures in the footnotes to its consolidated financial statements.