| Pay vs Performance Disclosure - USD ($) | 12 Months Ended |
| Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 |
| Pay vs Performance Disclosure | | | | |
| Pay vs Performance Disclosure, Table | AVERAGE AVERAGE SUMMARY COMPENSATION COMPENSATION ACTUALLY VALUE OF INITIAL FIXED $100 TABLE TOTAL PAID TO INVESTMENT BASED ON (4) : SUMMARY COMPENSATION FOR NON-CEO NON-CEO PEER GROUP COMPENSATION ACTUALLY NAMED NAMED TOTAL TOTAL NET ADJUSTED TABLE TOTAL PAID TO EXECUTIVE EXECUTIVE SHAREHOLDER SHAREHOLDER INCOME (LOSS) EBITDA (5) YEAR FOR CEO (1) CEO (2) OFFICERS (3) OFFICERS (2) , (3) RETURN RETURN ($M) ($M) (a) (b) (c) (d) (e) (f) (g) (h) (i) 2023 $11,355,216 $21,695,979 $4,427,539 $7,592,127 $92 $115 $(954) $738 2022 $11,733,864 $18,982,502 $4,213,127 $6,391,352 $66 $113 $(621) $816 2021 $13,715,358 $14,571,784 $4,735,382 $4,999,729 $40 $70 $(591) $995 2020 $6,491,804 $3,401,473 $2,619,786 $1,679,139 $34 $58 $(568) $1,201 (1) Amounts shown represent the total compensation reported for our CEO, Mr. Thigpen , in the Summary Compensation Table for fiscal years 2023, 2022, 2021 and 2020. (2) Amounts shown represent the amount of “compensation actually paid”, as computed in accordance with SEC rules. These amounts do not reflect the actual compensation paid to our CEO or other Named Executive Officers during the applicable year, but also include (i) the year-end value of equity awards granted during the reported year, (ii) the change in the value of equity awards that were unvested at the end of the prior year, measured through the date the awards vested or were forfeited, or through the end of the reported fiscal year, and (iii) certain pension-related costs. The valuation assumptions used to calculate fair values did not materially differ from those disclosed at the time of grant. Adjustment details are provided in the tables below. (3) Years 2023, 2022, 2021 and 2020 reflect compensation information for our Named Executive Officers, other than our CEO. Our Named Executive Officers, other than our CEO, for years 2023, 2022, 2021 and 2020 are Messrs. Mey, Adamson, Davis, and Long. (4) Reflects cumulative total shareholder return of the PHLX Oil Service Sector Index (OSX), as of December 31, 2023, weighted according to each companies’ market capitalization at the beginning of each period for which a return is indicated. The OSX is the peer group utilized by Transocean for purposes of Item 201(e) of Regulation S-K under the Exchange Act in Transocean’s annual report on Form 10-K for the year ended December 31, 2023. (5) The reconciliation of Adjusted EBITDA to net income in Appendix A of this proxy statement discloses how Adjusted EBITDA is calculated from the Company’s audited financial statements. | | | |
| Company Selected Measure Name | Adjusted EBITDA | | | |
| Named Executive Officers, Footnote | (1) Amounts shown represent the total compensation reported for our CEO, Mr. Thigpen , in the Summary Compensation Table for fiscal years 2023, 2022, 2021 and 2020. (3) Years 2023, 2022, 2021 and 2020 reflect compensation information for our Named Executive Officers, other than our CEO. Our Named Executive Officers, other than our CEO, for years 2023, 2022, 2021 and 2020 are Messrs. Mey, Adamson, Davis, and Long. | | | |
| Peer Group Issuers, Footnote | (4) Reflects cumulative total shareholder return of the PHLX Oil Service Sector Index (OSX), as of December 31, 2023, weighted according to each companies’ market capitalization at the beginning of each period for which a return is indicated. The OSX is the peer group utilized by Transocean for purposes of Item 201(e) of Regulation S-K under the Exchange Act in Transocean’s annual report on Form 10-K for the year ended December 31, 2023. | | | |
| PEO Total Compensation Amount | $ 11,355,216 | $ 11,733,864 | $ 13,715,358 | $ 6,491,804 |
| PEO Actually Paid Compensation Amount | $ 21,695,979 | 18,982,502 | 14,571,784 | 3,401,473 |
| Adjustment To PEO Compensation, Footnote | Summary Compensation Table to Compensation Actually Paid Adjustments 2023 ($) Summary Compensation Table $11,355,216 Adjustments to Determine Compensation Actually Paid for CEO Deduction for Change in the Actuarial Present Values reported under the “Change in Pension Value and Nonqualified Deferred Compensation Earnings” Column of the Summary Compensation Table - Increase for “Service Cost” for Pension Plans - Increase for “Prior Service Cost” for Pension Plans - Deduction for amounts reported under the “Stock Awards” column in the Summary Compensation Table ($8,308,561) Deduction for amounts reported under the “Option Awards” column in the Summary Compensation Table - Increase for fair value of awards granted during year that remain unvested as of year-end $8,471,555 Increase for fair value of awards granted during year that vest during year - Increase/deduction for change in fair value from prior year-end to current year-end of awards granted prior to year that were outstanding and unvested as of year-end $6,069,489 Increase/deduction for change in fair value from prior year-end to vesting date of awards granted prior to year that vested during year $4,108,280 Deduction of fair value of awards granted prior to year that were forfeited during year - Increase based on dividends or other earnings paid during year prior to vesting date of award - Total Adjustments $10,340,763 Compensation Actually Paid (CAP) to CEO $21,695,979 | | | |
| Non-PEO NEO Average Total Compensation Amount | $ 4,427,539 | 4,213,127 | 4,735,382 | 2,619,786 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 7,592,127 | 6,391,352 | 4,999,729 | 1,679,139 |
| Adjustment to Non-PEO NEO Compensation Footnote | Summary Compensation Table to Compensation Actually Paid Adjustments 2023 ($) Summary Compensation Table $4,427,539 Adjustments to Determine Average Compensation Actually Paid for Non-CEO Named Executive Officers Deduction for Change in the Actuarial Present Values reported under the “Change in Pension Value and Nonqualified Deferred Compensation Earnings” Column of the Summary Compensation Table ($15,084) Increase for “Service Cost” for Pension Plans - Increase for “Prior Service Cost” for Pension Plans - Deduction for amounts reported under the “Stock Awards” column in the Summary Compensation Table ($2,552,760) Deduction for amounts reported under the “Option Awards” column in the Summary Compensation Table - Increase for fair value of awards granted during year that remain unvested as of year-end $2,602,839 Increase for fair value of awards granted during year that vest during year - Increase/deduction for change in fair value from prior year-end to current year-end of awards granted prior to year that were outstanding and unvested as of year-end $1,862,822 Increase/deduction for change in fair value from prior year-end to vesting date of awards granted prior to year that vested during year $1,266,770 Deduction of fair value of awards granted prior to year that were forfeited during year - Increase based on dividends or other earnings paid during year prior to vesting date of award - Total Adjustments $3,164,587 Average Compensation Actually Paid (CAP) to Non-CEO Named Executive Officers $7,592,127 | | | |
| Compensation Actually Paid vs. Total Shareholder Return | | | | |
| Compensation Actually Paid vs. Net Income | | | | |
| Compensation Actually Paid vs. Company Selected Measure | | | | |
| Total Shareholder Return Vs Peer Group | | | | |
| Tabular List, Table | As described in detail in our CD&A, the Committee utilizes multiple key financial, operational, and sustainability measures to correlate our Named Executive Officer’s compensation to Company performance. In particular, the majority of compensation actually paid to our executives is based on the performance of Company stock. The key performance measures for 2023 are: COMPANY SELECTED METRICS Relative Total Shareholder Return Adjusted EBITDA Uptime ( 1) Sustainability ( 2) (1) This is a non-GAAP metric that is defined in the CD&A (2) Specific Company developed sustainability targets are explained in the CD&A | | | |
| Total Shareholder Return Amount | $ 92 | 66 | 40 | 34 |
| Peer Group Total Shareholder Return Amount | 115 | 113 | 70 | 58 |
| Net Income (Loss) | $ (954,000,000) | $ (621,000,000) | $ (591,000,000) | $ (568,000,000) |
| Company Selected Measure Amount | 738,000,000 | 816,000,000 | 995,000,000 | 1,201,000,000 |
| PEO Name | Mr. Thigpen | | | |
| Measure:: 1 | | | | |
| Pay vs Performance Disclosure | | | | |
| Name | Relative Total Shareholder Return | | | |
| Measure:: 2 | | | | |
| Pay vs Performance Disclosure | | | | |
| Name | Adjusted EBITDA | | | |
| Non-GAAP Measure Description | (5) The reconciliation of Adjusted EBITDA to net income in Appendix A of this proxy statement discloses how Adjusted EBITDA is calculated from the Company’s audited financial statements. | | | |
| Measure:: 3 | | | | |
| Pay vs Performance Disclosure | | | | |
| Name | Uptime( | | | |
| Measure:: 4 | | | | |
| Pay vs Performance Disclosure | | | | |
| Name | Sustainability( | | | |
| PEO | Total Adjustments | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | $ 10,340,763 | | | |
| PEO | Deduction for amounts reported under the "Stock Awards" column in the Summary Compensation Table | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | (8,308,561) | | | |
| PEO | Increase for fair value of awards granted during year that remain unvested as of year-end | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | 8,471,555 | | | |
| PEO | Increase/deduction for change in fair value from prior year-end to current year-end of awards granted prior to year that were outstanding and unvested as of year-end | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | 6,069,489 | | | |
| PEO | Increase/deduction for change in fair value from prior year-end to vesting date of awards granted prior to year that vested during year | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | 4,108,280 | | | |
| Non-PEO NEO | Total Adjustments | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | 3,164,587 | | | |
| Non-PEO NEO | Deduction for Change in the Actuarial Present Values reported under the "Change in Pension Value and Nonqualified Deferred Compensation Earnings" Column of the Summary Compensation Table | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | (15,084) | | | |
| Non-PEO NEO | Deduction for amounts reported under the "Stock Awards" column in the Summary Compensation Table | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | (2,552,760) | | | |
| Non-PEO NEO | Increase for fair value of awards granted during year that remain unvested as of year-end | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | 2,602,839 | | | |
| Non-PEO NEO | Increase/deduction for change in fair value from prior year-end to current year-end of awards granted prior to year that were outstanding and unvested as of year-end | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | 1,862,822 | | | |
| Non-PEO NEO | Increase/deduction for change in fair value from prior year-end to vesting date of awards granted prior to year that vested during year | | | | |
| Pay vs Performance Disclosure | | | | |
| Adjustment to Compensation, Amount | $ 1,266,770 | | | |
