General Information	3 Months Ended
Mar. 31, 2024
Accounting Policies [Abstract]
General Information	1. General Information The unaudited condensed consolidated financial statements of Diamond Offshore Drilling, Inc. and subsidiaries, which we refer to as “Diamond Offshore,” “Company,” “we,” “us” or “our,” should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2023. Interim Financial Information The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (or GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission. Accordingly, pursuant to such rules and regulations, they do not include all disclosures required by GAAP for annual financial statements. The condensed consolidated financial information has not been audited but, in the opinion of management, includes all adjustments (consisting of normal recurring adjustments) necessary for a fair presentation of Diamond Offshore’s condensed consolidated balance sheets, statements of operations, statements of comprehensive income, statements of stockholders’ equity and statements of cash flows at the dates and for the periods indicated. Results of operations for interim periods are not necessarily indicative of results of operations for the respective full years. Use of Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with GAAP 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 amount of revenues and expenses during the reporting period. Actual results could differ from those estimated. Restricted Cash We maintain a restricted cash bank account which is subject to restrictions pursuant to a management services agreement with an offshore drilling company. See Note 2 “Revenue from Contracts with Customers.” We classify such restricted cash accounts in current assets if the restrictions are expected to expire or otherwise be resolved within one year or if such funds are considered to offset current liabilities. At March 31, 2024 and December 31, 2023, our restricted cash was considered to be current and was recorded in “Restricted cash” in our unaudited Condensed Consolidated Balance Sheets. Asset Held for Sale We reported the $1.0 million carrying value of the Ocean Monarch as “Asset held for sale” in our unaudited Condensed Consolidated Balance Sheets at March 31, 2024. The rig was sold in April 2024 for aggregate proceeds of approximately $7.5 million. Accounting Principles Not Yet Adopted In December 2023, the Financial Accounting Standards Board (or FASB) issued Accounting Standards Update (or ASU) No. 2023-09, Income Tax (Topic 740): Improvements to Income Tax Disclosures (or ASU 2023-09). ASU 2023-09 requires business entities on an annual basis to (i) disclose specific categories in the rate reconciliation and (ii) provide additional information for reconciling items that meet certain quantitative thresholds. The new guidance is effective for public business entities for annual periods beginning after December 15, 2024. Early adoption is permitted. We are in the process of evaluating the impact of adopting this new guidance on our consolidated financial statement disclosures. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (or ASU 2023-07). ASU 2023-07 modifies the disclosure and presentation requirements of reportable segments and requires the disclosure of significant segment expenses that are regularly provided to the chief operating decision maker and included within each reported measure of segment profit and loss. In addition, the new guidance enhances interim disclosure requirements, clarifies circumstances in which an entity can disclose multiple segment measures of profit or loss, provides new segment disclosure requirements for entities with a single reportable segment, and contains other disclosure requirements. ASU 2023-07 is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We are in the process of evaluating the impact of adopting this new guidance on our consolidated financial statement disclosures.

General Information

3 Months Ended

Mar. 31, 2024

1. General Information

The unaudited condensed consolidated financial statements of Diamond Offshore Drilling, Inc. and subsidiaries, which we refer to as “Diamond Offshore,” “Company,” “we,” “us” or “our,” should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2023.

Interim Financial Information

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (or GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission. Accordingly, pursuant to such rules and regulations, they do not include all disclosures required by GAAP for annual financial statements. The condensed consolidated financial information has not been audited but, in the opinion of management, includes all adjustments (consisting of normal recurring adjustments) necessary for a fair presentation of Diamond Offshore’s condensed consolidated balance sheets, statements of operations, statements of comprehensive income, statements of stockholders’ equity and statements of cash flows at the dates and for the periods indicated. Results of operations for interim periods are not necessarily indicative of results of operations for the respective full years.

Use of Estimates in the Preparation of Financial Statements

The preparation of financial statements in conformity with GAAP 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 amount of revenues and expenses during the reporting period. Actual results could differ from those estimated.

Restricted Cash

We maintain a restricted cash bank account which is subject to restrictions pursuant to a management services agreement with an offshore drilling company. See Note 2 “Revenue from Contracts with Customers.”

We classify such restricted cash accounts in current assets if the restrictions are expected to expire or otherwise be resolved within one year or if such funds are considered to offset current liabilities. At March 31, 2024 and December 31, 2023, our restricted cash was considered to be current and was recorded in “Restricted cash” in our unaudited Condensed Consolidated Balance Sheets.

Asset Held for Sale

We reported the $1.0 million carrying value of the Ocean Monarch as “Asset held for sale” in our unaudited Condensed Consolidated Balance Sheets at March 31, 2024. The rig was sold in April 2024 for aggregate proceeds of approximately $7.5 million.

Accounting Principles Not Yet Adopted

In December 2023, the Financial Accounting Standards Board (or FASB) issued Accounting Standards Update (or ASU) No. 2023-09, Income Tax (Topic 740): Improvements to Income Tax Disclosures (or ASU 2023-09). ASU 2023-09 requires business entities on an annual basis to (i) disclose specific categories in the rate reconciliation and (ii) provide additional information for reconciling items that meet certain quantitative thresholds. The new guidance is effective for public business entities for annual periods beginning after December 15, 2024. Early adoption is permitted. We are in the process of evaluating the impact of adopting this new guidance on our consolidated financial statement disclosures.

In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (or ASU 2023-07). ASU 2023-07 modifies the disclosure and presentation requirements of reportable segments and requires the disclosure of significant segment expenses that are regularly

provided to the chief operating decision maker and included within each reported measure of segment profit and loss. In addition, the new guidance enhances interim disclosure requirements, clarifies circumstances in which an entity can disclose multiple segment measures of profit or loss, provides new segment disclosure requirements for entities with a single reportable segment, and contains other disclosure requirements. ASU 2023-07 is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We are in the process of evaluating the impact of adopting this new guidance on our consolidated financial statement disclosures.