| Cover Page - shares | 9 Months Ended | |
| Sep. 30, 2021 | Nov. 01, 2021 | |
| Cover [Abstract] | ||
| Document Type | 10-Q/A | |
| Amendment Flag | true | |
| Amendment Description | EXPLANATORY NOTE This Amendment No. 1 on Form 10-Q/A (or this Amendment) amends the Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2021 originally filed by Diamond Offshore Drilling, Inc., a Delaware corporation, with the Securities and Exchange Commission (or SEC) on November 8, 2021 (or the Original Filing). Unless the context indicates otherwise, references to “we”, “us”, “our” and the “company” refer to Diamond Offshore Drilling, Inc. and its subsidiaries. We are filing this Amendment solely to (a) amend Item 5 of Part II of the Original Filing to include information concerning our 2021 short-term incentive program that was inadvertently omitted from the Original Filing and (b) amend Item 6 of Part II of the Original Filing to include (i) an additional material contract, as Exhibit 10.4, and (ii) new certifications of our Chief Executive Officer and Chief Financial Officer, as Exhibits 31.1 and 31.2, pursuant to Rule 13a-14(a) of the Securities Exchange Act of 1934, as amended (or the Exchange Act). Because no financial statements have been included in this Amendment and this Amendment does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4 and 5 of the certifications have been omitted. We are not furnishing new certifications under Section 906 of the Sarbanes-Oxley Act of 2002 because no financial statements are being filed with this Amendment. The complete text of Item 5 of Part II has been set forth in its entirety in accordance with Rule 12b-15 under the Exchange Act. Except as described above, no other changes have been made to the Original Filing. The Original Filing continues to speak as of the date of the Original Filing, and we have not updated the disclosures contained therein to reflect any events occurring subsequent to the filing of the Original Filing other than as expressly indicated in this Amendment. Accordingly, this Amendment should be read in conjunction with the Original Filing and our other filings made with the SEC subsequent to November 8, 2021, including any amendments to those filings. | |
| Document Period End Date | Sep. 30, 2021 | |
| Document Fiscal Year Focus | 2021 | |
| Document Fiscal Period Focus | Q3 | |
| Entity Registrant Name | DIAMOND OFFSHORE DRILLING, INC. | |
| Entity Central Index Key | 0000949039 | |
| Current Fiscal Year End Date | --12-31 | |
| Entity Filer Category | Non-accelerated Filer | |
| Entity Small Business | false | |
| Entity Emerging Growth Company | false | |
| Entity Shell Company | false | |
| Entity Bankruptcy Proceedings, Reporting Current | true | |
| Entity Common Stock, Shares Outstanding | 100,074,948 | |
| Entity Current Reporting Status | Yes | |
| Entity File Number | 1-13926 | |
| Entity Incorporation, State or Country Code | DE | |
| Entity Tax Identification Number | 76-0321760 | |
| Entity Address, Address Line One | 15415 Katy Freeway | |
| Entity Address, City or Town | Houston | |
| Entity Address, State or Province | TX | |
| Entity Address, Postal Zip Code | 77094 | |
| City Area Code | 281 | |
| Local Phone Number | 492-5300 | |
| Document Quarterly Report | true | |
| Document Transition Report | false | |
| Entity Interactive Data Current | Yes |
