| Document and Entity Information - USD ($) | 12 Months Ended | ||
| Dec. 31, 2020 | Feb. 04, 2021 | Jun. 30, 2020 | |
| Cover [Abstract] | |||
| Document Type | 10-K/A | ||
| Amendment Flag | true | ||
| Amendment Description | EXPLANATORY NOTE This Amendment No. 1 on Form 10-K/A, or this Amendment, amends the Annual Report on Form 10-K for the fiscal year ended December 31, 2020 originally filed by Diamond Offshore Drilling, Inc., a Delaware corporation, with the Securities and Exchange Commission, or SEC, on February 10, 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 present the information required by Items 10, 11, 12, 13 and 14 of Part III of Form 10-K because we will not file our definitive proxy statement within 120 days of the end of our fiscal year ended December 31, 2020. This Amendment also amends and restates Item 15 of Part IV of the Original Filing solely to include the filing of new certifications of our Chief Executive Officer and Chief Financial Officer, as Exhibits 31.1 and 31.2, pursuant to Rule 15d-14(a) of the Securities Exchange Act of 1934, as amended. 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. 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 the Company’s other filings made with the SEC subsequent to February 10, 2021. | ||
| Document Period End Date | Dec. 31, 2020 | ||
| Document Fiscal Year Focus | 2020 | ||
| Document Fiscal Period Focus | FY | ||
| 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 Common Stock, Shares Outstanding | 138,054,311 | ||
| Entity Public Float | $ 16,882,138 | ||
| 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 Annual Report | true | ||
| Document Transition Report | false | ||
| Entity Interactive Data Current | Yes | ||
| Entity Well-known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| ICFR Auditor Attestation Flag | false | ||
| Documents Incorporated by Reference | None. |
