Transocean (RIG) 10-K 20 Feb 24 2023 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Feb. 14, 2024	Jun. 30, 2023
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38373
Entity Registrant Name	TRANSOCEAN LTD
Entity Incorporation, State or Country Code	V8
Entity Tax Identification Number	98-0599916
Entity Address, Address Line One	Turmstrasse 30
Entity Address, City or Town	Steinhausen
Entity Address, Country	CH
Entity Address, Postal Zip Code	6312
City Area Code	+41 (41)
Local Phone Number	749-0500
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		809,030,846
Entity Central Index Key	0001451505
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
Title of 12(b) Security	Shares
Trading Symbol	RIG
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Document Financial Statement Error Correction [Flag]	false
ICFR Auditor Attestation Flag	true
Entity Public Float			$ 5,370
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Houston, Texas

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating revenues
Contract drilling revenues	$ 2,832	$ 2,575	$ 2,556
Revenue from Contract with Customer, Product and Service [Extensible List]	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember
Costs and expenses
Operating and maintenance	$ 1,986	$ 1,679	$ 1,697
Cost, Product and Service [Extensible List]	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember
Depreciation and amortization	$ 744	$ 735	$ 742
General and administrative	187	182	167
Total costs and expenses	2,917	2,596	2,606
Loss on impairment of assets	(57)
Loss on disposal of assets, net	(183)	(10)	(62)
Operating loss	(325)	(31)	(112)
Other income (expense), net
Interest income	52	27	15
Interest expense, net of amounts capitalized	(646)	(561)	(447)
Gain (loss) on retirement of debt	(31)	8	51
Other, net	9	(5)	23
Total other income (expense), net	(616)	(531)	(358)
Loss before income tax expense	(941)	(562)	(470)
Income tax expense	13	59	121
Net loss	(954)	(621)	(591)
Net income attributable to noncontrolling interest			1
Net loss attributable to controlling interest	$ (954)	$ (621)	$ (592)
Loss per share, basic (in dollars per share)	$ (1.24)	$ (0.89)	$ (0.93)
Loss per share, diluted (in dollars per share)	$ (1.24)	$ (0.89)	$ (0.93)
Weighted-average shares, basic (in shares)	768	699	637
Weighted-average shares, diluted (in shares)	768	699	637

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (954)	$ (621)	$ (591)
Net income attributable to noncontrolling interest			1
Net loss attributable to controlling interest	(954)	(621)	(592)
Components of net periodic benefit costs before reclassifications	6	(109)	175
Components of net periodic benefit costs reclassified to net loss		3	10
Other comprehensive income (loss) before income taxes	6	(106)	185
Income taxes related to other comprehensive income (loss)	2	5	(6)
Other comprehensive income (loss)	8	(101)	179
Other comprehensive income (loss) attributable to controlling interest	8	(101)	179
Total comprehensive loss	(946)	(722)	(412)
Total comprehensive income attributable to noncontrolling interest			1
Total comprehensive loss attributable to controlling interest	$ (946)	$ (722)	$ (413)

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Assets
Cash and cash equivalents	$ 762	$ 683
Accounts receivable, net	512	485
Materials and supplies, net	426	388
Restricted cash and cash equivalents	233	308
Other current assets	193	144
Total current assets	2,126	2,008
Property and equipment	23,875	24,217
Less accumulated depreciation	(6,934)	(6,748)
Property and equipment, net	16,941	17,469
Contract intangible assets	4	56
Deferred tax assets, net	44	13
Other assets	1,139	890
Total assets	20,254	20,436
Liabilities and equity
Accounts payable	323	281
Accrued income taxes	23	19
Debt due within one year	370	719
Other current liabilities	681	539
Total current liabilities	1,397	1,558
Long-term debt	7,043	6,628
Deferred tax liabilities, net	540	493
Other long-term liabilities	858	965
Total long-term liabilities	8,441	8,086
Commitments and contingencies
Shares, CHF 0.10 par value, 1,021,294,549 authorized, 142,362,093 conditionally authorized, 843,715,858 issued and 809,030,846 outstanding at December 31, 2023, and 905,093,509 authorized, 142,362,675 conditionally authorized, 797,244,753 issued and 721,888,427 outstanding at December 31, 2022	81	71
Additional paid-in capital	14,544	13,984
Accumulated deficit	(4,033)	(3,079)
Accumulated other comprehensive loss	(177)	(185)
Total controlling interest shareholders' equity	10,415	10,791
Noncontrolling interest	1	1
Total equity	10,416	10,792
Total liabilities and equity	$ 20,254	$ 20,436

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - SFr / shares	Dec. 31, 2023	Dec. 31, 2022
CONSOLIDATED BALANCE SHEETS
Shares, CHF par value (in Swiss francs per share)	SFr 0.10	SFr 0.10
Shares, authorized	1,021,294,549	905,093,509
Shares, conditionally authorized	142,362,093	142,362,675
Shares, issued	843,715,858	797,244,753
Shares, outstanding	809,030,846	721,888,427

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Millions, $ in Millions	Total controlling interest shareholders' equity	Shares	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Noncontrolling interest	Total
Balance at Dec. 31, 2020	$ 11,432	$ 60	$ 13,501	$ (1,866)	$ (263)	$ 3	$ 11,435
Balance (in shares) at Dec. 31, 2020		615
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss							(412)
Total comprehensive loss attributable to controlling interest	(413)						(413)
Share-based compensation	28		28				28
Issuance of shares	158	$ 4	154				158
Issuance of shares (in shares)		40
Net loss attributable to controlling interest				(592)			(592)
Other comprehensive income (loss) attributable to controlling interest					179		179
Total comprehensive income attributable to noncontrolling interest						1
Acquisition of noncontrolling interest						(3)	(3)
Balance at Dec. 31, 2021	11,205	$ 64	13,683	(2,458)	(84)	1	11,206
Balance (in shares) at Dec. 31, 2021		655
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss							(722)
Total comprehensive loss attributable to controlling interest	(722)						(722)
Share-based compensation	29		29				29
Issuance of shares	263	$ 7	256				263
Issuance of shares (in shares)		67
Issuance of warrants	16		16				16
Net loss attributable to controlling interest				(621)			(621)
Other comprehensive income (loss) attributable to controlling interest					(101)		(101)
Balance at Dec. 31, 2022	10,791	$ 71	13,984	(3,079)	(185)	1	10,792
Balance (in shares) at Dec. 31, 2022		722
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss							(946)
Total comprehensive loss attributable to controlling interest	(946)						(946)
Share-based compensation	40		40				40
Issuance of shares	530	$ 10	520				530
Issuance of shares (in shares)		87
Net loss attributable to controlling interest				(954)			(954)
Other comprehensive income (loss) attributable to controlling interest					8		8
Balance at Dec. 31, 2023	$ 10,415	$ 81	$ 14,544	$ (4,033)	$ (177)	$ 1	$ 10,416
Balance (in shares) at Dec. 31, 2023		809

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net loss	$ (954)	$ (621)	$ (591)
Adjustments to reconcile to net cash provided by operating activities:
Amortization of contract intangible asset	52	117	220
Depreciation and amortization	744	735	742
Share-based compensation expense	40	29	28
Loss on impairment of assets	57
Loss on impairment of investment in unconsolidated affiliates	5		37
Loss on disposal of assets, net	183	10	62
Fair value adjustment to bifurcated compound exchange feature	127	157
Amortization of debt-related balances, net	51	33	25
(Gain) loss on retirement of debt	31	(8)	(51)
Deferred income tax expense	18	46	128
Other, net	43	44	52
Changes in deferred revenues, net	70	(20)	(108)
Changes in deferred costs, net	(190)	1	(6)
Changes in other operating assets and liabilities, net	(113)	(75)	37
Net cash provided by operating activities	164	448	575
Cash flows from investing activities
Capital expenditures	(427)	(717)	(208)
Investments in equity of unconsolidated affiliates	(10)	(42)	(1)
Investment in loans to unconsolidated affiliates	(3)	(5)	(33)
Proceeds from disposal of assets, net	10	7	9
Cash acquired in acquisition of unconsolidated affiliate	7
Net cash used in investing activities	(423)	(757)	(233)
Cash flows from financing activities
Repayments of debt	(1,717)	(554)	(606)
Proceeds from issuance of debt, net of issue costs	1,983	175
Proceeds from issuance of shares, net of issue costs		263	158
Proceeds from issuance of warrants, net of issue costs		12
Other, net	(3)	(8)	(42)
Net cash provided by (used in) financing activities	263	(112)	(490)
Net increase (decrease) in unrestricted and restricted cash and cash equivalents	4	(421)	(148)
Unrestricted and restricted cash and cash equivalents, beginning of period	991	1,412	1,560
Unrestricted and restricted cash and cash equivalents, end of period	$ 995	$ 991	$ 1,412

Business

Business	12 Months Ended
	Dec. 31, 2023
Business
Business	Note 1—Business Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. As of December 31, 2023, we owned or had partial ownership interests in and operated a fleet of 37 mobile offshore drilling units, consisting of 28 ultra-deepwater floaters and nine harsh environment floaters. As of December 31, 2023, we were constructing one ultra-deepwater drillship. We provide, as our primary business, contract drilling services in a single operating segment, which involves contracting our mobile offshore drilling rigs, related equipment and work crews to drill oil and gas wells. We specialize in technically demanding regions of the global offshore drilling business with a particular focus on ultra-deepwater and harsh environment drilling services. Our drilling fleet is one of the most versatile fleets in the world, consisting of drillships and semisubmersible floaters used in support of offshore drilling activities and offshore support services on a worldwide basis. We perform contract drilling services by deploying our high-specification fleet in a single

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Significant Accounting Policies
Significant Accounting Policies	Note 2—Significant Accounting Policies Accounting estimates Fair value measurements Consolidation Note 4—Unconsolidated Affiliates Note 14—Equity Functional currency Revenues and related pre-operating costs over the contract period unless otherwise constrained. We recognize revenues from contract terminations as we fulfill our obligations and all contingencies have been resolved. We apply the optional exemption that permits us to exclude disclosure of the estimated transaction price related to the variable portion of unsatisfied performance obligations at the end of the reporting period, as our transaction price is typically based on a single performance obligation consisting of a series of distinct hourly, or more frequent, periods, the variability of which will be resolved at the time of the future services. To obtain contracts with our customers, we incur pre-operating costs to prepare a rig for contract and mobilize a rig to the drilling location. We defer such pre-operating contract preparation and mobilization costs for recognition in operating and maintenance costs over the estimated contract period on a straight-line basis, consistent with the general pace of activity. See Note 5—Revenues Income taxes We maintain liabilities for estimated tax exposures in our jurisdictions of operation, and we recognize the provisions and benefits resulting from changes to those liabilities in our income tax expense or benefit along with related interest and penalties. Income tax exposure items include potential challenges to permanent establishment positions, intercompany pricing, disposition transactions, and withholding tax rates and their applicability. These tax exposures are resolved primarily through the settlement of audits within these tax jurisdictions or by judicial means, but can also be affected by changes in applicable tax law or other factors, which could cause us to revise past estimates. We measure deferred tax assets and liabilities using enacted tax rates that will apply in the years in which the deferred tax assets and liabilities are expected to be recovered or paid. In evaluating our ability to realize deferred tax assets, we consider all available positive and negative evidence, including projected future taxable income and the existence of cumulative losses in recent years. We record a valuation allowance for deferred tax assets when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. For example, we may record a valuation allowance for deferred tax assets resulting from net operating losses incurred during the year in certain jurisdictions for which the benefit of the losses will not be realized or for foreign tax credit carryforwards that may expire prior to their utilization. See Note 11—Income Taxes Cash and cash equivalents Restricted cash and cash equivalents Note 9—Debt Materials and supplies Property and equipment We capitalize expenditures for newbuilds, renewals, replacements and improvements, including capitalized interest, if applicable, and we recognize the expense for maintenance and repair costs as incurred. For newbuild construction projects, we also capitalize the initial preparation, mobilization and commissioning costs incurred until the drilling unit is placed into service. Upon sale or other disposition of an asset, we recognize a net gain or loss on disposal of the asset, which is measured as the difference between the net carrying amount of the asset and the net proceeds received. We compute depreciation using the straight-line method after allowing for salvage values. The estimated original useful life of our drilling units is 35 years, our buildings and improvements range from three four Long lived asset impairment ultra-deepwater floaters and harsh environment floaters. When an impairment of one or more of our asset groups is indicated, we measure an impairment as the amount by which the carrying amount of the asset group exceeds its estimated fair value. We measure the fair values of our asset groups by applying a variety of valuation methods, incorporating a combination of income, market and cost approaches, using projected discounted cash flows and estimates of the exchange price that would be received for the assets in the principal or most advantageous market for the assets in an orderly transaction between market participants as of the measurement date. For an asset classified as held for sale, we consider the asset to be impaired to the extent its carrying amount exceeds its estimated fair value less cost to sell. See Note 7—Long-Lived Assets Equity investments and impairment Note 4—Unconsolidated Affiliates Pension and other postemployment benefit plans We measure the actuarially determined obligations and related costs for our defined benefit pension and other postemployment benefit plans, retiree life insurance and medical benefits, by applying assumptions, the most significant of which include long-term rate of return on plan assets, discount rates and mortality rates. For the long-term rate of return, we develop our assumptions regarding the expected rate of return on plan assets based on historical experience and projected long-term investment returns, and we weight the assumptions based on each plan’s asset allocation. For the discount rate, we base our assumptions on a yield curve approach using Aa-rated corporate bonds and the expected timing of future benefit payments. At December 31, 2023 and 2022, the funded status of our pension and other postemployment benefit plans represented an aggregate liability of $125 million and $174 million, respectively, and an aggregate asset of $31 million and $44 million, respectively. See Note 10—Postemployment Benefit Plans Share based compensation Note 15—ShareBased Compensation Contingencies

Accounting Standards Update

Accounting Standards Update	12 Months Ended
	Dec. 31, 2023
Accounting Standards Update
Accounting Standards Update	Note 3—Accounting Standards Update Recently issued accounting standards updates not yet adopted Segment reporting operating decision-maker. The update, which permits early adoption, is effective for annual periods beginning after December 15, 2023 and must be applied retrospectively to all periods presented, unless impracticable. We continue to evaluate the requirements and do not expect our adoption to have a material effect on our consolidated statements of financial position, operations or cash flows or on the disclosures contained in our notes to consolidated financial statements. Income taxes

Unconsolidated Affiliates

Unconsolidated Affiliates	12 Months Ended
	Dec. 31, 2023
Unconsolidated Affiliates
Unconsolidated Affiliates	Note 4—Unconsolidated Affiliates Equity investments Overview Transocean Norge In the years ended December 31, 2023, 2022 and 2021, we recognized a net loss of $14 million, $24 million and $10 million, respectively, recorded in other income and expense, associated with equity in losses of our equity investments. At December 31, 2023 and 2022, the aggregate carrying amount of our equity investments was $216 million and $113 million, respectively, recorded in other assets. Contributions Ocean Rig Olympia Note 7—Long-Lived Assets Impairments Related party transactions Operating activities Transocean Norge Transocean Norge Transocean Norge In the years ended December 31, 2023, 2022 and 2021, we incurred costs of approximately $55 million, $54 million and $24 million, respectively, for Transocean Norge operating and maintenance costs, and made an aggregate cash payment of $27 million, $10 million and $15 million, respectively, to charter the rig and rent other equipment from Orion. In the years ended December 31, 2023, 2022 and 2021, we made an aggregate cash payment of $12 million, $7 million and $6 million, respectively, to other unconsolidated affiliates for research and development and for equipment to reduce emissions and improve reliability. At December 31, 2023 and 2022, our accounts receivable from affiliates was $14 million and $32 million, respectively, recorded in other current assets, and our accounts payable to affiliates was $4 million and $2 million, respectively, recorded in accounts payable. Acquisition Deepwater Aquila Note 7—Long Lived Note 14—Equity Debt investments Transocean Norge

Revenues

Revenues	12 Months Ended
	Dec. 31, 2023
Revenues
Revenues	Note 5—Revenues Overview Disaggregation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ ​ Year ended December 31, 2022 ​ ​ Year ended December 31, 2021 ​ ​ ​ Ultra- Harsh ​ ​ ​ ​ Ultra- ​ Harsh ​ ​ ​ ​ Ultra- ​ Harsh ​ ​ ​ ​ ​ ​ deepwater environment ​ ​ ​ ​ deepwater ​ environment ​ ​ ​ ​ deepwater ​ environment ​ ​ ​ ​ ​ floaters floaters ​ Total ​ ​ floaters ​ floaters ​ Total ​ ​ floaters ​ floaters ​ Total ​ U.S. $ 1,433 ​ $ — ​ $ 1,433 ​ ​ $ 1,135 ​ $ — ​ $ 1,135 ​ ​ $ 1,096 ​ $ 2 ​ $ 1,098 ​ Norway ​ ​ — ​ ​ 603 ​ ​ 603 ​ ​ ​ — ​ ​ 835 ​ ​ 835 ​ ​ ​ — ​ ​ 790 ​ ​ 790 ​ Brazil ​ ​ 298 ​ ​ — ​ ​ 298 ​ ​ ​ 240 ​ ​ — ​ ​ 240 ​ ​ ​ 237 ​ ​ — ​ ​ 237 ​ Other countries (a) ​ ​ 341 ​ ​ 157 ​ ​ 498 ​ ​ ​ 333 ​ ​ 32 ​ ​ 365 ​ ​ ​ 387 ​ ​ 44 ​ ​ 431 ​ Total contract drilling revenues $ 2,072 ​ $ 760 ​ $ 2,832 ​ ​ $ 1,708 ​ $ 867 ​ $ 2,575 ​ ​ $ 1,720 ​ $ 836 ​ $ 2,556 ​ (a) The aggregate contract drilling revenues earned in other countries that individually represented less than 10 percent of total contract drilling revenues. Major customers ​ Contract liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2023 2022 Deferred contract revenues, recorded in other current liabilities $ 165 ​ $ 124 ​ Deferred contract revenues, recorded in other long-term liabilities ​ ​ 233 ​ ​ 204 ​ Total contract liabilities $ 398 ​ $ 328 ​ Significant changes in contract liabilities were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended ​ ​ ​ December 31, ​ ​ 2023 2022 Total contract liabilities, beginning of period ​ $ 328 ​ $ 348 ​ Decrease due to recognition of revenues for goods and services ​ ​ (189) ​ ​ (119) ​ Increase due to goods and services transferred over time ​ ​ 259 ​ ​ 99 ​ Total contract liabilities, end of period ​ $ 398 ​ $ 328 ​ ​ Pre-operating costs

Contract Intangible Assets

Contract Intangible Assets	12 Months Ended
	Dec. 31, 2023
Contract Intangible Assets
Contract Intangible Assets	Note 6—Contract Intangible Assets The gross carrying amount and accumulated amortization of our drilling contract intangible assets were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ ​ Gross ​ ​ ​ ​ Net ​ Gross ​ ​ ​ ​ Net ​ ​ carrying ​ Accumulated ​ carrying ​ carrying ​ Accumulated ​ carrying ​ amount ​ amortization ​ amount amount amortization amount Drilling contract intangible assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period $ 907 ​ $ (851) ​ $ 56 ​ $ 907 ​ $ (734) $ 173 ​ Amortization ​ ​ — ​ ​ (52) ​ ​ (52) ​ ​ — ​ ​ (117) ​ ​ (117) ​ Balance, end of period $ 907 ​ $ (903) ​ $ 4 ​ $ 907 ​ $ (851) $ 56 ​ ​ We expect to recognize the remaining $4 million balance in contract drilling revenues in the three months ending March 31, 2024.

Long- Lived Assets

Long- Lived Assets	12 Months Ended
	Dec. 31, 2023
Long-Lived Assets
Long -Lived Assets	Note 7—Long-Lived Assets Disaggregation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Long-lived assets ​ ​ ​ ​ ​ ​ ​ U.S. $ 7,472 ​ $ 6,514 ​ Greece ​ ​ 2,652 ​ ​ 3,022 ​ Norway ​ ​ 2,103 ​ ​ 3,255 ​ Other countries (a) ​ ​ 5,200 ​ ​ 5,171 ​ Total long-lived assets $ 17,427 ​ $ 17,962 ​ (a) The aggregate carrying amount of long-lived assets located in other countries that individually represented less than 10 percent of total long-lived assets. Because the majority of our assets are mobile, the geographic locations of such assets at the end of the periods are not necessarily indicative of the geographic distribution of the operating revenues generated by such assets during the periods presented. Our international operations are subject to certain political and other uncertainties, including risks of war and civil disturbances or other market disrupting events, expropriation of equipment, repatriation of income or capital, taxation policies, and the general hazards associated with certain areas in which we operate. Although we are organized under the laws of Switzerland, we have minimal assets located in Switzerland, and we do not conduct any operations or earn operating revenues in Switzerland. Construction work in progress ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 Construction work in progress, beginning of period ​ $ 1,195 ​ $ 1,017 ​ $ 828 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital expenditures ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ 331 ​ ​ 669 ​ ​ 174 ​ Other equipment and construction projects ​ ​ 96 ​ ​ 48 ​ ​ 34 ​ Total capital expenditures ​ ​ 427 ​ ​ 717 ​ ​ 208 ​ Non-cash capital additions acquired in exchange for issuance of shares ​ ​ 126 ​ ​ — ​ ​ — ​ Non-cash capital additions financed under Shipyard Loans ​ ​ — ​ ​ 382 ​ ​ — ​ Changes in accrued capital additions ​ ​ 5 ​ ​ 3 ​ ​ 13 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Property and equipment placed into service ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ (1,157) ​ ​ (882) ​ ​ — ​ Other equipment and construction projects ​ ​ (74) ​ ​ (42) ​ ​ (32) ​ Construction work in progress, end of period ​ $ 522 ​ $ 1,195 ​ $ 1,017 ​ ​ In the years ended December 31, 2023, 2022 and 2021, we capitalized interest costs of $39 million, $73 million and $50 million, respectively, for our construction work in progress. Acquisition Deepwater Aquila Note 4—Unconsolidated Affiliates Note 14—Equity Disposals Ocean Rig Olympia Note 4—Unconsolidated Affiliates Leiv Eiriksson Impairment Paul B. Loyd, Jr Transocean Leader Assets held for sale Paul B. Loyd, Jr Transocean Leader

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases
Leases	Note 8—Leases Overview Our finance lease for the ultra-deepwater drillship Petrobras 10000 Lease costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ Lease costs ​ 2023 2022 2021 ​ Short-term lease costs ​ $ 4 ​ $ 14 ​ $ 17 ​ Operating lease costs ​ ​ 14 ​ ​ 12 ​ ​ 12 ​ Finance lease costs, amortization of right-of-use asset ​ ​ 20 ​ ​ 20 ​ ​ 20 ​ Finance lease costs, interest on lease liability ​ ​ 27 ​ ​ 30 ​ ​ 33 ​ Total lease costs ​ $ 65 ​ $ 76 ​ $ 82 ​ ​ Lease payments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 2022 2021 ​ Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 17 ​ $ 14 ​ $ 13 ​ Operating cash flows from finance lease ​ ​ — ​ ​ 8 ​ ​ 37 ​ Financing cash flows from finance lease ​ ​ — ​ ​ 3 ​ ​ 33 ​ ​ At December 31, 2023, the aggregate future minimum lease payments were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Finance ​ ​ ​ ​ ​ ​ leases ​ lease ​ Years ending December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ ​ ​ $ 19 ​ $ 65 ​ 2025 ​ ​ ​ ​ ​ 19 ​ ​ 70 ​ 2026 ​ ​ ​ ​ ​ 18 ​ ​ 71 ​ 2027 ​ ​ ​ ​ ​ 15 ​ ​ 70 ​ 2028 ​ ​ ​ ​ ​ 13 ​ ​ 71 ​ Thereafter ​ ​ ​ ​ ​ 89 ​ ​ 47 ​ Total future minimum rental payment ​ ​ ​ ​ ​ 173 ​ ​ 394 ​ Less amount representing imputed interest ​ ​ ​ ​ ​ (53) ​ ​ (75) ​ Present value of future minimum rental payments ​ ​ ​ ​ ​ 120 ​ ​ 319 ​ Current portion, recorded in other current liabilities ​ ​ ​ ​ ​ 12 ​ ​ 43 ​ Long-term lease liabilities, recorded in other long-term liabilities ​ ​ ​ ​ $ 108 ​ $ 276 ​ ​

Debt

Debt	12 Months Ended
	Dec. 31, 2023
Debt
Debt	Note 9—Debt Overview Outstanding debt ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal amount ​ ​ Carrying amount ​ ​ ​ ​ December 31, ​ December 31, ​ December 31, ​ December 31, ​ ​ 2023 2022 2023 2022 0.50% Exchangeable Senior Bonds due January 2023 ​ (a) ​ $ — ​ $ 49 ​ ​ $ — ​ $ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ (b) ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ (b) ​ ​ — ​ ​ 352 ​ ​ ​ — ​ ​ 350 ​ 7.75% Senior Secured Notes due October 2024 ​ (b) ​ ​ — ​ ​ 240 ​ ​ ​ — ​ ​ 238 ​ 6.25% Senior Secured Notes due December 2024 ​ (b) ​ ​ — ​ ​ 250 ​ ​ ​ — ​ ​ 248 ​ 6.125% Senior Secured Notes due August 2025 ​ (b) ​ ​ — ​ ​ 336 ​ ​ ​ — ​ ​ 332 ​ 7.25% Senior Notes due November 2025 ​ (c) ​ ​ 354 ​ ​ 354 ​ ​ ​ 352 ​ ​ 351 ​ 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ (d) ​ ​ 234 ​ ​ 294 ​ ​ ​ 221 ​ ​ 271 ​ 7.50% Senior Notes due January 2026 ​ (c) ​ ​ 569 ​ ​ 569 ​ ​ ​ 567 ​ ​ 566 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ (d) ​ ​ — ​ ​ 238 ​ ​ ​ — ​ ​ 265 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ (d) ​ ​ 687 ​ ​ 687 ​ ​ ​ 938 ​ ​ 1,008 ​ 6.875% Senior Secured Notes due February 2027 ​ (b) ​ ​ 413 ​ ​ 482 ​ ​ ​ 409 ​ ​ 477 ​ 8.00% Senior Notes due February 2027 ​ (c) ​ ​ 612 ​ ​ 612 ​ ​ ​ 609 ​ ​ 608 ​ 7.45% Notes due April 2027 ​ (a) ​ ​ 52 ​ ​ 52 ​ ​ ​ 52 ​ ​ 52 ​ 8.00% Debentures due April 2027 ​ (a) ​ ​ 22 ​ ​ 22 ​ ​ ​ 22 ​ ​ 22 ​ 4.50% Shipyard Loans due September 2027 ​ (e) ​ ​ 420 ​ ​ 439 ​ ​ ​ 384 ​ ​ 389 ​ 8.375% Senior Secured Notes due February 2028 ​ (b) ​ ​ 525 ​ ​ — ​ ​ ​ 518 ​ ​ — ​ 7.00% Notes due June 2028 ​ (e) ​ ​ 261 ​ ​ 261 ​ ​ ​ 264 ​ ​ 264 ​ 8.00% Senior Secured Notes due September 2028 ​ (b) ​ ​ 325 ​ ​ — ​ ​ ​ 321 ​ ​ — ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ (c) ​ ​ 259 ​ ​ 300 ​ ​ ​ 486 ​ ​ 440 ​ 8.75% Senior Secured Notes due February 2030 ​ (f) ​ ​ 1,116 ​ ​ — ​ ​ ​ 1,094 ​ ​ — ​ 7.50% Notes due April 2031 ​ (a) ​ ​ 396 ​ ​ 396 ​ ​ ​ 395 ​ ​ 394 ​ 6.80% Senior Notes due March 2038 ​ (a) ​ ​ 610 ​ ​ 610 ​ ​ ​ 605 ​ ​ 605 ​ 7.35% Senior Notes due December 2041 ​ (a) ​ ​ 177 ​ ​ 177 ​ ​ ​ 176 ​ ​ 176 ​ Total debt ​ ​ ​ ​ 7,032 ​ ​ 6,963 ​ ​ ​ 7,413 ​ ​ 7,347 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less debt due within one year ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 0.50% Exchangeable Senior Bonds due January 2023 ​ (a) ​ ​ — ​ ​ 49 ​ ​ ​ — ​ ​ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ (b) ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ (b) ​ ​ — ​ ​ 83 ​ ​ ​ — ​ ​ 81 ​ 7.75% Senior Secured Notes due October 2024 ​ (b) ​ ​ — ​ ​ 60 ​ ​ ​ — ​ ​ 59 ​ 6.25% Senior Secured Notes due December 2024 ​ (b) ​ ​ — ​ ​ 62 ​ ​ ​ — ​ ​ 61 ​ 6.125% Senior Secured Notes due August 2025 ​ (b) ​ ​ — ​ ​ 66 ​ ​ ​ — ​ ​ 64 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ (d) ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ 6 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ (d) ​ ​ — ​ ​ — ​ ​ ​ 71 ​ ​ 70 ​ 6.875% Senior Secured Notes due February 2027 ​ (b) ​ ​ 83 ​ ​ 69 ​ ​ ​ 81 ​ ​ 67 ​ 4.50% Shipyard Loans due September 2027 ​ (e) ​ ​ 90 ​ ​ 20 ​ ​ ​ 75 ​ ​ 20 ​ 8.00% Senior Secured Notes due September 2028 ​ (b) ​ ​ 30 ​ ​ — ​ ​ ​ 30 ​ ​ — ​ 8.75% Senior Secured Notes due February 2030 ​ (f) ​ ​ 117 ​ ​ — ​ ​ ​ 113 ​ ​ — ​ Total debt due within one year ​ ​ ​ ​ 320 ​ ​ 652 ​ ​ ​ 370 ​ ​ 719 ​ Total long-term debt ​ $ 6,712 ​ $ 6,311 ​ $ 7,043 ​ $ 6,628 ​ (a) Transocean Inc., a wholly owned direct subsidiary of Transocean Ltd., is the issuer of the notes and debentures (the “Legacy Guaranteed Notes”). The Legacy Guaranteed Notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. (b) Each subsidiary issuer of the respective unregistered notes is a wholly owned indirect subsidiary of Transocean Inc. The senior secured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd., Transocean Inc. and, in each case, the owner of the respective collateral rig or rigs. (c) Transocean Inc. is the issuer of the unregistered notes (collectively, the “Priority Guaranteed Notes”). The guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean Inc. and rank equal in right of payment of all our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Legacy Guaranteed Notes, the 4.50% shipyard loans due September 2027 (each, a “Shipyard Loan”, and together, the “Shipyard Loans”) and the 7.00% notes due June 2028 and structurally subordinate to the Senior Priority Guaranteed Notes, as defined below, to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (d) Transocean Inc. is the issuer of the unregistered notes (together, the “Senior Priority Guaranteed Notes”). The priority guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean Inc. and rank equal in right of payment of all of our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Priority Guaranteed Notes to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (e) The subsidiary borrowers under the Shipyard Loans and the subsidiary issuer of the registered notes are wholly owned indirect subsidiaries of Transocean Inc. The loans and notes are fully and unconditionally guaranteed by Transocean Inc. (f) Transocean Inc. is the issuer of the unregistered notes. The senior secured notes are fully and unconditionally guaranteed on an unsecured basis by Transocean Ltd. and on a limited senior secured basis by each of the wholly owned subsidiary owners of the collateral rigs. Transocean Ltd. and Transocean Inc. are not subject to any significant restrictions on their ability to obtain funds from their consolidated subsidiaries by dividends, loans or capital distributions. Indentures The indentures that govern the 4.00% senior guaranteed exchangeable bonds due December 2025 (the “4.00% Senior Guaranteed Exchangeable Bonds”) and the 4.625% senior guaranteed exchangeable bonds due September 2029 (the “4.625% Senior Guaranteed Exchangeable Bonds”) require such bonds to be repurchased upon the occurrence of certain fundamental changes and events, at specified prices depending on the particular fundamental change or event, which include changes and events related to certain (i) change of control events applicable to Transocean Ltd. or Transocean Inc., (ii) the failure of our shares to be listed or quoted on a national securities exchange and (iii) specified tax matters. The indentures that govern the 6.875% senior secured notes due February 2027, the 8.375% senior secured notes due February 2028 (the “8.375% Senior Secured Notes”) and the 8.75% senior secured notes due February 2030 (the “8.75% Senior Secured Notes”) contain covenants that limit the ability of our subsidiaries that own or operate the collateral rigs to declare or pay dividends to their affiliates. The indentures that govern our senior secured notes contain certain lien requirements. At December 31, 2023, we had restricted cash and cash equivalents of $198 million deposited in restricted accounts to satisfy debt service and reserve requirements for the senior secured notes. At December 31, 2023, the rigs encumbered for the senior secured notes and our Shipyard Loans, including Deepwater Aquila Deepwater Atlas Deepwater Pontus Deepwater Poseidon Deepwater Proteus Deepwater Thalassa Deepwater Titan Transocean Enabler Transocean Encourage Interest rate adjustments Scheduled maturities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Other Total ​ installments installments installments Years ending December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ $ 320 ​ $ 71 ​ $ 391 ​ 2025 ​ ​ 1,068 ​ ​ 72 ​ ​ 1,140 ​ 2026 ​ ​ 1,110 ​ ​ 72 ​ ​ 1,182 ​ 2027 ​ ​ 1,900 ​ ​ 36 ​ ​ 1,936 ​ 2028 ​ ​ 664 ​ ​ — ​ ​ 664 ​ Thereafter ​ ​ 1,970 ​ ​ — ​ ​ 1,970 ​ Total installments ​ $ 7,032 ​ $ 251 ​ ​ 7,283 ​ Total unamortized debt-related balances, net ​ ​ ​ ​ ​ ​ ​ ​ (220) ​ Bifurcated compound exchange feature, at estimated fair value ​ ​ ​ ​ ​ ​ ​ ​ 350 ​ Total carrying amount of debt ​ ​ ​ ​ ​ ​ ​ $ 7,413 ​ ​ Credit agreements Secured Credit Facility Deepwater Asgard Deepwater Corcovado Deepwater Invictus Deepwater Mykonos Deepwater Orion Deepwater Skyros Development Driller III Dhirubhai Deepwater KG2 Discoverer Inspiration Transocean Barents Transocean Spitsbergen The Secured Credit Facility contains covenants that, among other things, include maintenance of a minimum guarantee coverage ratio of 3.0 to 1.0, a minimum collateral coverage ratio of 2.1 to 1.0, a maximum debt to capitalization ratio of 0.60 to 1.00 and minimum liquidity of $500 million. The Secured Credit Facility also restricts the ability of Transocean Ltd. and certain of our subsidiaries to, among other things, merge, consolidate or otherwise make changes to the corporate structure, incur liens, incur additional indebtedness, enter into transactions with affiliates and pay dividends and other distributions. In order to utilize the Secured Credit Facility, we must, at the time of the borrowing request, be in full compliance with the terms and conditions of the Secured Credit Facility and make certain representations and warranties, including with respect to compliance with laws and solvency, to the lenders. Repayment of borrowings under the Secured Credit Facility are subject to acceleration upon the occurrence of an event of default. Under the agreements governing certain of our debt and finance lease, we are also subject to various covenants, including restrictions on creating liens, engaging in sale/leaseback transactions and engaging in certain merger, consolidation or reorganization transactions. A default under our public debt indentures, the agreements governing our senior secured notes, our finance lease contract or any other debt owed to unaffiliated entities that exceeds $125 million could trigger a default under the Secured Credit Facility and, if not waived by the lenders, could cause us to lose access to the Secured Credit Facility. At December 31, 2023, based on the credit rating of the Secured Credit Facility on that date, the Secured Credit Facility Margin was 2.875 percent and the facility fee was 0.625 percent. At December 31, 2023, we had no borrowings outstanding, $13 million of letters of credit issued, and we had $587 million of available borrowing capacity under the Secured Credit Facility. Shipyard financing arrangement Deepwater Atlas Deepwater Titan Deepwater Atlas Deepwater Titan Deepwater Atlas Deepwater Titan Exchangeable bonds Exchange terms ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Implied ​ ​ ​ ​ ​ Exchange ​ exchange Shares ​ ​ rate ​ price issuable 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ 190.4762 ​ $ 5.25 ​ ​ 44.5 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ 290.6618 ​ $ 3.44 ​ ​ 75.3 ​ ​ The exchange rates, identified above, are subject to adjustment upon the occurrence of certain events. The 4.00% Senior Guaranteed Exchangeable Bonds may be exchanged by holders at any time prior to the close of business on the second business day immediately preceding the maturity date and, at our election, such exchange may be settled by delivering cash, Transocean Ltd. shares or a combination of cash and shares. The 4.625% Senior Guaranteed Exchangeable Bonds may be exchanged by holders at any time prior to the close of business on the second business day immediately preceding the maturity date or redemption date and, at our election, such exchange may be settled by delivering cash, Transocean Ltd. shares or a combination of cash and shares. Effective interest rates and fair values ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective Fair ​ ​ ​ ​ ​ interest rate value 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ ​ ​ ​ 6.9% ​ $ 341 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ ​ ​ ​ 18.3% ​ $ 567 ​ ​ We estimated the fair values of the exchangeable debt instruments, including the exchange features, by employing a binomial lattice model using significant other observable inputs, representative of Level 2 fair value measurements, including the terms and credit spreads of our debt and the expected volatility of the market price for our shares. Interest expense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Contractual interest ​ $ 24 ​ $ 16 ​ $ 11 ​ Amortization ​ ​ 19 ​ ​ 9 ​ ​ 5 ​ Bifurcated compound exchange feature ​ ​ 127 ​ ​ 157 ​ ​ — ​ Total ​ $ 170 ​ $ 182 ​ $ 16 ​ ​ The 4.625% Senior Guaranteed Exchangeable Bonds contain a compound exchange feature that, in addition to the exchange terms outlined above, requires us to pay holders a make whole premium of future interest through March 30, 2028, for exchanges exercised during a redemption notice period. Such compound exchange feature must be bifurcated from the host debt instrument since it is not considered indexed to our stock. Accordingly, we recognize changes to the liability for the estimated fair value of the bifurcated compound exchange feature with a corresponding adjustment to interest expense. At December 31, 2023 and 2022, the carrying amount of the bifurcated compound exchange feature, recorded as a component of the carrying amount of debt, was $350 million and $295 million, respectively. Exchanges In July 2023, the holders of the remaining outstanding $25 million aggregate principal amount of 2.50% Senior Guaranteed Exchangeable Bonds exchanged such bonds under the terms of the governing indenture at the applicable exchange rate of 162.1626 Transocean Ltd. shares per $1,000 note. As part of the transaction, we delivered 4.0 million Transocean Ltd. shares. In October 2023, holders of $60 million and $41 million aggregate principal amount of the 4.00% Senior Guaranteed Exchangeable Bonds and the 4.625% Senior Guaranteed Exchangeable Bonds, respectively, exchanged such bonds under the terms of the governing indenture at the applicable exchange rate of 190.4762 and 290.6618 Transocean Ltd. shares, respectively, per $1,000 note. As part of the transactions, we delivered an aggregate 26.5 million Transocean Ltd. shares, including an aggregate 3.1 million additional shares to such holders. Debt issuance Senior secured notes— Deepwater Titan In January 2023, we issued $1.175 billion aggregate principal amount of 8.75% Senior Secured Notes, and we received $1.148 billion aggregate cash proceeds, net of issue costs. The 8.75% Senior Secured Notes are secured by a lien on the ultra-deepwater floaters Deepwater Pontus Deepwater Proteus Deepwater Thalassa Transocean Enabler Transocean Encourage In October 2023, we issued $325 million aggregate principal amount of 8.00% senior secured notes due September 2028 (the “8.00% Senior Secured Notes”), and we received $319 million aggregate cash proceeds, net of issue costs. The 8.00% Senior Secured Notes are secured by the assets and certain earnings associated with the ultra-deepwater floater Deepwater Aquila Senior guaranteed exchangeable bonds Exchangeable Bonds. In the year ended December 31, 2022, as a result of the 2022 Private Exchange, we recognized a gain of $6 million ($0.01 per diluted share), with no tax effect, associated with the retirement of debt. Additionally, we sold $188 million aggregate principal amount of the 4.625% Senior Guaranteed Exchangeable Bonds and issued 15.5 million warrants to purchase Transocean Ltd. shares for aggregate net cash proceeds of $188 million. On or after March 30, 2026, we may redeem for cash all or a portion of the 4.625% Senior Guaranteed Exchangeable Bonds at a price equivalent to the aggregate principal amount to be redeemed if the closing price of our shares has been greater than 115 percent of the exchange price for a period of at least 20 trading days. The initial carrying amount of the 4.625% Senior Guaranteed Exchangeable Bonds, measured at the estimated fair value on the date of issuance, was $281 million. We estimated the fair value of the exchangeable debt instrument, including the exchange feature, by employing a binomial lattice model and by using significant other observable inputs, representative of Level 2 fair value measurements, including the terms and credit spreads of our debt and expected volatility of the market price for our shares. See Note 14—Equity In February 2021, we issued $294 million aggregate principal amount of the 4.00% Senior Guaranteed Exchangeable Bonds and made an aggregate cash payment of $11 million in private exchanges (the “2021 Private Exchange”) for $323 million aggregate principal amount of the 0.50% Exchangeable Senior Bonds. In the year ended December 31, 2021, as a result of the 2021 Private Exchange, we recognized a gain of $51 million ($0.08 per diluted share), with no tax effect, associated with the retirement of debt. The initial carrying amount of the 4.00% Senior Guaranteed Exchangeable Bonds, measured at the estimated fair value on the date of issuance, was $260 million. We estimated the fair value of the exchangeable debt instrument, including the exchange feature, by employing a binomial lattice model using significant other observable inputs, representative of Level 2 fair value measurements, including the terms and credit spreads of our debt and expected volatility of the market price for our shares. Debt repayment, redemption, and retirement Early retirement ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ ​ 2022 ​ ​ 2021 ​ ​ Redeemed ​ ​ Redeemed ​ Exchanged ​ Total ​ Redeemed Exchanged Total 5.52% Senior Secured Notes due May 2022 ​ $ — ​ ​ $ 18 ​ $ — ​ $ 18 ​ ​ $ — ​ $ — ​ $ — ​ 3.80% Senior Notes due October 2022 ​ ​ — ​ ​ ​ 27 ​ ​ — ​ ​ 27 ​ ​ ​ — ​ ​ — ​ ​ — ​ 0.50% Exchangeable Senior Bonds due January 2023 ​ ​ — ​ ​ ​ 18 ​ ​ 73 ​ ​ 91 ​ ​ ​ — ​ ​ 323 ​ ​ 323 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ 243 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 11 ​ ​ — ​ ​ 11 ​ 5.875% Senior Secured Notes due January 2024 ​ ​ 311 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 68 ​ ​ — ​ ​ 68 ​ 7.75% Senior Secured Notes due October 2024 ​ ​ 240 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ — ​ ​ — ​ 6.25% Senior Secured Notes due December 2024 ​ ​ 250 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ — ​ ​ — ​ 6.125% Senior Secured Notes due August 2025 ​ ​ 336 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ — ​ ​ — ​ 7.25% Senior Notes due November 2025 ​ ​ — ​ ​ ​ 14 ​ ​ 43 ​ ​ 57 ​ ​ ​ — ​ ​ — ​ ​ — ​ Aggregate principal amount of debt retired ​ $ 1,380 ​ ​ $ 77 ​ $ 116 ​ $ 193 ​ ​ $ 79 ​ $ 323 ​ $ 402 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate cash payment ​ $ 1,402 ​ ​ $ 75 ​ $ — ​ $ 75 ​ ​ $ 79 ​ $ 11 ​ $ 90 ​ Aggregate principal amount of debt issued in exchanges ​ $ — ​ ​ $ — ​ $ 112 ​ $ 112 ​ ​ $ — ​ $ 294 ​ $ 294 ​ Aggregate fair value of warrants issued in exchanges ​ $ — ​ ​ $ — ​ $ 5 ​ $ 5 ​ ​ $ — ​ $ — ​ $ — ​ Aggregate net gain (loss) ​ $ (32) ​ ​ $ 2 ​ $ 6 ​ $ 8 ​ ​ $ — ​ $ 51 ​ $ 51 ​ ​ Additionally, in the year ended December 31, 2023, we recognized a net gain of $1 million associated with the retirement of $41 million aggregate principal amount of the 4.625% Senior Guaranteed Exchangeable Bonds exchanged by holders in October 2023. Scheduled maturities and installments

Postemployment Benefit Plans

Postemployment Benefit Plans	12 Months Ended
	Dec. 31, 2023
Postemployment Benefit Plans
Postemployment Benefit Plans	Note 10—Postemployment Benefit Plans Defined contribution plans We sponsor defined contribution plans for our employees in most markets in which we operate worldwide, the most significant of which were as follows: (1) a qualified savings plan covering certain eligible employees working in the U.S., (2) various savings plans covering eligible employees working in Norway, (3) a non-qualified savings plan covering certain eligible employees working outside the U.S., the United Kingdom (“U.K.”) and Norway and (4) a qualified savings plan covering certain eligible employees working in the U.K. In the years ended December 31, 2023, 2022 and 2021, we recognized expense of $58 million, $61 million and $52 million, respectively, recorded in the same financial statement line item as cash compensation paid to the respective employees, related to our defined contribution plans. Defined benefit pension and other postemployment benefit plans Overview Net periodic benefit costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ Year ended December 31, 2021 ​ ​ U.S. ​ U.K. ​ OPEB ​ U.S. ​ U.K. ​ OPEB ​ U.S. ​ Non-U.S. OPEB ​ ​ Plans Plan Plans Plans Plan Plans Plans Plans Plans ​ Discount rate ​ 5.06 % 4.80 % 4.92 % 2.92 % 1.90 % 1.83 % 2.60 % 1.50 % 1.21 % Expected rate of return ​ 6.41 % 5.00 % na ​ 4.81 % 2.00 % na ​ 5.51 % 3.20 % na ​ “na” means not applicable. The components of net periodic benefit costs, recognized in other income and expense, were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ Year ended December 31, 2021 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ U.S. ​ Non-U.S. ​ OPEB ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Plans Plans Plans Total Net periodic benefit costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest cost ​ $ 65 ​ $ 9 ​ $ — ​ $ 74 ​ $ 50 ​ $ 6 ​ $ — ​ $ 56 ​ $ 47 ​ $ 6 ​ $ — ​ $ 53 ​ Expected return on plan assets ​ ​ (84) ​ ​ (11) ​ ​ — ​ ​ (95) ​ ​ (65) ​ ​ (7) ​ ​ — ​ ​ (72) ​ ​ (66) ​ ​ (13) ​ ​ — ​ ​ (79) ​ Settlements and curtailments ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (2) ​ ​ — ​ ​ (2) ​ Actuarial loss, net ​ ​ — ​ ​ 2 ​ ​ — ​ ​ 2 ​ ​ 5 ​ ​ — ​ ​ — ​ ​ 5 ​ ​ 11 ​ ​ 1 ​ ​ — ​ ​ 12 ​ Prior service gain, net ​ ​ — ​ ​ — ​ ​ (2) ​ ​ (2) ​ ​ — ​ ​ — ​ ​ (2) ​ ​ (2) ​ ​ — ​ ​ — ​ ​ (2) ​ ​ (2) ​ Net periodic benefit costs (income) ​ $ (19) ​ $ — ​ $ (2) ​ $ (21) ​ $ (10) ​ $ (1) ​ $ (2) ​ $ (13) ​ $ (8) ​ $ (8) ​ $ (2) ​ $ (18) ​ ​ Funded status ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ ​ ​ ​ ​ Plans Plan Plans Plans Plan Plans Discount rate ​ ​ ​ ​ ​ ​ ​ 4.88 % 4.50 % 4.80 % 5.06 % 4.80 % 4.92 % Expected long-term rate of return ​ ​ ​ ​ ​ ​ ​ 6.80 % 5.10 % na ​ 6.41 % 5.00 % na ​ “na” means not applicable. The changes in funded status, balance sheet classifications and accumulated benefit obligations were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Change in projected benefit obligation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Projected benefit obligation, beginning of period $ 1,307 ​ $ 188 ​ $ 10 ​ $ 1,505 ​ $ 1,724 ​ $ 348 ​ $ 13 ​ $ 2,085 ​ Actuarial (gain) loss, net ​ ​ 32 ​ ​ 11 ​ ​ — ​ ​ 43 ​ ​ (391) ​ ​ (119) ​ ​ (1) ​ ​ (511) ​ Interest cost ​ ​ 65 ​ ​ 9 ​ ​ — ​ ​ 74 ​ ​ 50 ​ ​ 6 ​ ​ — ​ ​ 56 ​ Currency exchange rate (gain) loss ​ ​ — ​ ​ 11 ​ ​ — ​ ​ 11 ​ ​ — ​ ​ (37) ​ ​ — ​ ​ (37) ​ Benefits paid ​ ​ (76) ​ ​ (11) ​ ​ (2) ​ ​ (89) ​ ​ (76) ​ ​ (10) ​ ​ (2) ​ ​ (88) ​ Projected benefit obligation, end of period ​ ​ 1,328 ​ ​ 208 ​ ​ 8 ​ ​ 1,544 ​ ​ 1,307 ​ ​ 188 ​ ​ 10 ​ ​ 1,505 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in plan assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value of plan assets, beginning of period ​ ​ 1,143 ​ ​ 232 ​ ​ — ​ ​ 1,375 ​ ​ 1,621 ​ ​ 434 ​ ​ — ​ ​ 2,055 ​ Actual return (loss) on plan assets ​ ​ 138 ​ ​ 6 ​ ​ — ​ ​ 144 ​ ​ (403) ​ ​ (147) ​ ​ — ​ ​ (550) ​ Currency exchange rate gain (loss) ​ ​ — ​ ​ 12 ​ ​ — ​ ​ 12 ​ ​ — ​ ​ (45) ​ ​ — ​ ​ (45) ​ Employer contributions ​ ​ 6 ​ ​ — ​ ​ 2 ​ ​ 8 ​ ​ 1 ​ ​ — ​ ​ 2 ​ ​ 3 ​ Benefits paid ​ ​ (76) ​ ​ (11) ​ ​ (2) ​ ​ (89) ​ ​ (76) ​ ​ (10) ​ ​ (2) ​ ​ (88) ​ Fair value of plan assets, end of period ​ ​ 1,211 ​ ​ 239 ​ ​ — ​ ​ 1,450 ​ ​ 1,143 ​ ​ 232 ​ ​ — ​ ​ 1,375 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Funded status asset (liability), end of period $ (117) ​ $ 31 ​ $ (8) ​ $ (94) ​ $ (164) ​ $ 44 ​ $ (10) ​ $ (130) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance sheet classification, end of period: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pension asset, non-current $ — ​ $ 31 ​ $ — ​ $ 31 ​ $ — ​ $ 44 ​ $ — ​ $ 44 ​ Pension liability, current ​ ​ (1) ​ ​ — ​ ​ (3) ​ ​ (4) ​ ​ (1) ​ ​ — ​ ​ (3) ​ ​ (4) ​ Pension liability, non-current ​ ​ (116) ​ ​ — ​ ​ (5) ​ ​ (121) ​ ​ (163) ​ ​ — ​ ​ (7) ​ ​ (170) ​ Accumulated other comprehensive loss (income), before taxes ​ ​ 144 ​ ​ 90 ​ ​ (6) ​ ​ 228 ​ ​ 166 ​ ​ 76 ​ ​ (8) ​ ​ 234 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated benefit obligation, end of period ​ $ 1,328 ​ $ 208 ​ $ 8 ​ $ 1,544 ​ $ 1,307 ​ $ 188 ​ $ 10 ​ $ 1,505 ​ ​ Because our defined benefit plans no longer accrue benefits for participants, the projected benefit obligation is equivalent to the accumulated benefit obligation. Certain amounts related to plans with a projected benefit obligation and accumulated benefit obligation in excess of plan assets were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Projected benefit obligation / accumulated benefit obligation $ 1,328 ​ $ — ​ $ 8 ​ $ 1,336 ​ $ 1,307 ​ $ — ​ $ 10 ​ $ 1,317 ​ Fair value of plan assets ​ ​ 1,211 ​ ​ — ​ ​ — ​ ​ 1,211 ​ ​ 1,143 ​ ​ — ​ ​ — ​ ​ 1,143 ​ ​ The amounts in accumulated other comprehensive loss (income) that have not been recognized were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Actuarial (gain) loss, net $ 144 ​ $ 88 ​ $ (1) ​ $ 231 ​ $ 166 ​ $ 74 ​ $ (1) ​ $ 239 ​ Prior service cost (credit), net ​ ​ — ​ ​ 2 ​ ​ (5) ​ ​ (3) ​ ​ — ​ ​ 2 ​ ​ (7) ​ ​ (5) ​ Accumulated other comprehensive loss (income), before taxes $ 144 ​ $ 90 ​ $ (6) ​ $ 228 ​ $ 166 ​ $ 76 ​ $ (8) ​ $ 234 ​ ​ Plan assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ Target allocation ​ Actual allocation ​ Target allocation ​ Actual allocation ​ ​ U.S. ​ U.K. ​ U.S. ​ U.K. ​ U.S. ​ U.K. ​ U.S. ​ U.K. ​ Plans Plan Plans Plan Plans Plan Plans Plan Equity securities ​ 38 % 20 % 37 % 21 % 38 % 20 % 38 % 24 % Fixed income securities ​ 62 % 73 % 62 % 72 % 62 % 80 % 61 % 74 % Other investments ​ — % 7 % 1 % 7 % — ​ — % 1 ​ 2 % Total ​ 100 % 100 % 100 % 100 % 100 % 100 % 100 % 100 % ​ We periodically review our investment policies, plan assets and asset allocation strategies to evaluate performance relative to specified objectives. In determining our asset allocation strategies for the U.S. Plans, we review the results of regression models to assess the most appropriate target allocation for each plan, given the plan’s status, demographics and duration. For the U.K. Plan, the plan trustees establish the asset allocation strategies consistent with the regulations of the U.K. pension regulators and in consultation with financial advisors and company representatives. Investment managers for the U.S. Plans and the U.K. Plan are given established ranges within which the investments may deviate from the target allocations. The investments for the funded defined benefit plans were categorized as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ Significant observable inputs ​ Significant other observable inputs ​ Total ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. equity funds $ 316 ​ $ — ​ $ 316 ​ $ — ​ $ — ​ $ — ​ $ 316 ​ $ — ​ $ 316 ​ Non-U.S. equity funds ​ ​ 139 ​ ​ — ​ ​ 139 ​ ​ — ​ ​ 51 ​ ​ 51 ​ ​ 139 ​ ​ 51 ​ ​ 190 ​ Bond funds ​ ​ 746 ​ ​ — ​ ​ 746 ​ ​ 4 ​ ​ 171 ​ ​ 175 ​ ​ 750 ​ ​ 171 ​ ​ 921 ​ Total mutual funds ​ ​ 1,201 ​ ​ — ​ ​ 1,201 ​ ​ 4 ​ ​ 222 ​ ​ 226 ​ ​ 1,205 ​ ​ 222 ​ ​ 1,427 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and money market funds ​ ​ 6 ​ ​ 1 ​ ​ 7 ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 1 ​ ​ 7 ​ Synthetic leveraged credit fund ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 16 ​ ​ 16 ​ ​ — ​ ​ 16 ​ ​ 16 ​ Total other investments ​ ​ 6 ​ ​ 1 ​ ​ 7 ​ ​ — ​ ​ 16 ​ ​ 16 ​ ​ 6 ​ ​ 17 ​ ​ 23 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total investments $ 1,207 ​ $ 1 ​ $ 1,208 ​ $ 4 ​ $ 238 ​ $ 242 ​ $ 1,211 ​ $ 239 ​ $ 1,450 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Significant observable inputs ​ Significant other observable inputs ​ Total ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. equity funds $ 301 ​ $ — ​ $ 301 ​ $ — ​ $ — ​ $ — ​ $ 301 ​ $ — ​ $ 301 ​ Non-U.S. equity funds ​ ​ 132 ​ ​ — ​ ​ 132 ​ ​ 4 ​ ​ 57 ​ ​ 61 ​ ​ 136 ​ ​ 57 ​ ​ 193 ​ Bond funds ​ ​ 698 ​ ​ — ​ ​ 698 ​ ​ 2 ​ ​ 171 ​ ​ 173 ​ ​ 700 ​ ​ 171 ​ ​ 871 ​ Total mutual funds ​ ​ 1,131 ​ ​ — ​ ​ 1,131 ​ ​ 6 ​ ​ 228 ​ ​ 234 ​ ​ 1,137 ​ ​ 228 ​ ​ 1,365 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and money market funds ​ ​ 6 ​ ​ 4 ​ ​ 10 ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 4 ​ ​ 10 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total investments $ 1,137 ​ $ 4 ​ $ 1,141 ​ $ 6 ​ $ 228 ​ $ 234 ​ $ 1,143 ​ $ 232 ​ $ 1,375 ​ ​ We estimated the fair values of the plan assets by applying the market approach, as categorized above, using either (i) significant observable inputs, representative of Level 1 fair value measurements, including market prices of actively traded funds, or (ii) significant other observable inputs, representative of Level 2 fair value measurements, including market prices of the underlying securities in the trust funds. The U.S. Plans and the U.K. Plan invest in passively and actively managed funds that are referenced to or benchmarked against market indices. The plan investment managers have discretion to select securities within each asset category. Given this discretion, the plans may occasionally hold either long or short positions in our debt or equity securities. Since plan investment managers are required to maintain well diversified portfolios, the actual investment in our securities would be immaterial relative to asset categories and the overall plan assets. Funding contributions and benefit payments The projected benefits payments were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Years ending December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 $ 84 ​ $ 6 ​ $ 3 ​ $ 93 ​ 2025 ​ ​ 84 ​ ​ 7 ​ ​ 3 ​ ​ 94 ​ 2026 ​ ​ 84 ​ ​ 8 ​ ​ 1 ​ ​ 93 ​ 2027 ​ ​ 85 ​ ​ 8 ​ ​ — ​ ​ 93 ​ 2028 ​ ​ 85 ​ ​ 9 ​ ​ — ​ ​ 94 ​ 2029 - 2033 ​ ​ 427 ​ ​ 58 ​ ​ 1 ​ ​ 486 ​ ​

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Taxes
Income Taxes	Note 11—Income Taxes Overview Tax provision and rate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ 2023 2022 2021 Current tax expense (benefit) $ (5) ​ $ 13 ​ $ (7) ​ Deferred tax expense ​ ​ 18 ​ ​ 46 ​ ​ 128 ​ Income tax expense $ 13 ​ $ 59 ​ $ 121 ​ ​ In the years ended December 31, 2023, 2022 and 2021, our effective tax rate was (1.4) percent, (10.4) percent and (25.7) percent, respectively, based on loss before income tax expense. The relationship between our provision for or benefit from income taxes and our income or loss before income taxes can vary significantly from period to period considering, among other factors, (a) the overall level of income before income taxes, (b) changes in the blend of income that is taxed based on gross revenues rather than income before taxes, (c) rig movements between taxing jurisdictions and (d) our rig operating structures. A reconciliation of the income tax benefit computed at the Swiss holding company federal statutory rate of 7.83% and our reported consolidated income tax expense was as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ 2023 2022 2021 Income tax benefit at Swiss federal statutory rate $ (74) ​ $ (44) ​ $ (36) ​ Earnings subject to rates different than the Swiss federal statutory rate ​ ​ 129 ​ ​ 52 ​ ​ 78 ​ Deemed profits taxes ​ ​ 11 ​ ​ 10 ​ ​ 17 ​ Withholding taxes ​ ​ 5 ​ ​ 12 ​ ​ 10 ​ Changes in valuation allowance ​ ​ (23) ​ ​ 79 ​ ​ 1,167 ​ Changes in unrecognized tax benefits, net ​ ​ (37) ​ ​ 2 ​ ​ (43) ​ Swiss Federal Act on Tax Reform and AHV Financing ​ ​ — ​ ​ 96 ​ ​ (1,095) ​ Audit settlement ​ ​ — ​ ​ 12 ​ ​ — ​ Changes due to organizational restructuring ​ ​ — ​ ​ (162) ​ ​ 16 ​ Losses on impairment ​ ​ — ​ ​ — ​ ​ 5 ​ Other, net ​ ​ 2 ​ ​ 2 ​ ​ 2 ​ Income tax expense $ 13 ​ $ 59 ​ $ 121 ​ ​ In January 2020, Switzerland made effective the Federal Act on Tax Reform and AHV Financing (“TRAF”). In March 2020, we entered into discussions with the Swiss tax authorities regarding the manner by which the TRAF applies to certain Swiss subsidiaries, which allows us to access historic depreciation and costs related to financing assets not previously deducted on Swiss tax returns, which can be apportioned to offset taxable income based on the remaining useful lives of the rigs and financing assets. In the three months ended December 31, 2021, we reached an agreement with the Swiss Tax authorities regarding the TRAF treatment. At December 31, 2023 and 2022, we had a deferred tax liability of $264 million and $226 million, respectively, and a deferred tax asset of $1.21 billion and $1.23 billion, respectively, offset with a valuation allowance of $1.10 billion, associated with TRAF. Deferred taxes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Deferred tax assets ​ ​ ​ ​ ​ ​ ​ Swiss historic depreciation and financing asset costs ​ $ 1,210 ​ $ 1,226 ​ Net operating loss carryforwards ​ 1,264 ​ ​ 1,115 ​ Interest expense limitation ​ ​ 87 ​ ​ 77 ​ United Kingdom charter limitation ​ ​ 53 ​ ​ 53 ​ Accrued expenses ​ ​ 47 ​ ​ 36 ​ Tax credits ​ ​ 4 ​ ​ 11 ​ Deferred income ​ ​ — ​ ​ 7 ​ Accrued payroll costs not currently deductible ​ ​ 16 ​ ​ 18 ​ Loss contingencies ​ ​ 4 ​ ​ 4 ​ Other ​ ​ 54 ​ ​ 43 ​ Valuation allowance ​ ​ (1,884) ​ ​ (1,910) ​ Total deferred tax assets, net of allowance ​ ​ 855 ​ ​ 680 ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ Depreciation ​ ​ (1,342) ​ ​ (1,150) ​ Other ​ ​ (9) ​ ​ (10) ​ Total deferred tax liabilities ​ ​ (1,351) ​ ​ (1,160) ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets (liabilities), net $ (496) ​ $ (480) ​ ​ We include taxes related to the earnings of all of our subsidiaries since we do not consider the earnings of any of our subsidiaries to be indefinitely reinvested. At December 31, 2023 and 2022, our deferred tax assets included U.S. tax credits of $4 million and $11 million, respectively, which will expire between 2024 and 2026. Deferred tax assets related to our net operating losses were generated in various worldwide tax jurisdictions. At December 31, 2023, our net deferred tax assets related to our net operating loss carryforwards included $585 million, which do not expire, and $855 million, which will expire between 2024 and 2041. As of December 31, 2023, our consolidated cumulative loss incurred over the recent three-year period represented significant objective negative evidence for the evaluation of the realizability of our deferred tax assets. Because such evidence has limited our ability to consider other subjective evidence, we evaluate each jurisdiction separately. We consider objective evidence, such as contract backlog activity, in jurisdictions in which we have profitable contracts, and the ability to carryback losses or utilize losses against potential exposures. If estimated future taxable income changes during the carryforward periods or if the cumulative loss is no longer present, we may adjust the amount of deferred tax assets that we expect to realize. At December 31, 2023 and 2022, due to uncertainty of realization, we had a valuation allowance of $1.88 billion and $1.91 billion, respectively, on net operating losses and other deferred tax assets due to the uncertainty of realization. Unrecognized tax benefits ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ 2023 ​ 2022 ​ 2021 Balance, beginning of period $ 444 ​ $ 402 ​ $ 378 ​ Additions for current year tax positions ​ ​ 45 ​ ​ 28 ​ ​ 28 ​ Additions for prior year tax positions ​ ​ 5 ​ ​ 62 ​ ​ 46 ​ Reductions related to statute of limitation expirations and changes in law ​ ​ (14) ​ ​ (13) ​ ​ (19) ​ Reductions due to settlements ​ ​ (5) ​ ​ (5) ​ ​ (31) ​ Reductions for prior year tax positions ​ ​ (26) ​ ​ (30) ​ ​ — ​ Balance, end of period $ 449 ​ $ 444 ​ $ 402 ​ ​ Our unrecognized tax benefits, including related interest and penalties that we recognize as a component of income tax expense, were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2023 ​ 2022 Unrecognized tax benefits, excluding interest and penalties ​ $ 449 ​ $ 444 ​ Interest and penalties ​ ​ 9 ​ ​ 27 ​ Unrecognized tax benefits, including interest and penalties ​ $ 458 ​ $ 471 ​ ​ In the years ended December 31, 2023, 2022 and 2021, we recognized, as a component of our income tax provision, benefit of $18 million, expense of $6 million and expense of $8 million, respectively, related to interest and penalties associated with our unrecognized tax benefits. As of December 31, 2023, we have unrecognized benefits of $458 million, including interest and penalties, against which we have recorded net operating loss deferred tax assets of $411 million, resulting in net unrecognized tax benefits of $47 million, including interest and penalties, that upon reversal would favorably impact our effective tax rate. During the year ending December 31, 2024, it is reasonably possible that our existing liabilities for unrecognized tax benefits may increase or decrease, primarily due to the progression of open audits and the expiration of statutes of limitation. However, we cannot reasonably estimate a range of potential changes in our existing liabilities for unrecognized tax benefits due to various uncertainties, such as the unresolved nature of various audits. Tax positions and returns Brazil tax investigations

Loss Per Share

Loss Per Share	12 Months Ended
	Dec. 31, 2023
Loss per share
Loss per share	Note 12—Loss Per Share The computation of basic and diluted loss per share was as follows (in millions, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Numerator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to controlling interest ​ $ (954) ​ $ (621) ​ $ (592) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares for per share calculation ​ ​ 768 ​ ​ 699 ​ ​ 637 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss per share, basic and diluted ​ $ (1.24) ​ $ (0.89) ​ $ (0.93) ​ ​ We excluded from the computations certain shares issuable as follows because the effect would have been antidilutive (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Exchangeable bonds ​ ​ 150.8 ​ ​ 128.1 ​ ​ 104.4 ​ Share-based awards ​ ​ 18.6 ​ ​ 15.5 ​ ​ 12.6 ​ Warrants ​ ​ 10.2 ​ ​ — ​ ​ — ​ ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies
Commitments and Contingencies	Note 13—Commitments and Contingencies Purchase and service agreement obligations We have purchase obligations with shipyards and other contractors primarily related to our newbuild construction program for Deepwater Aquila ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service ​ ​ ​ Purchase ​ agreement ​ ​ obligations ​ obligations ​ Years ending December 31, ​ ​ ​ ​ ​ ​ ​ 2024 $ 19 ​ $ 131 ​ 2025 ​ ​ 2 ​ ​ 145 ​ 2026 ​ ​ — ​ ​ 149 ​ 2027 ​ ​ — ​ ​ 121 ​ 2028 ​ ​ — ​ ​ 73 ​ Thereafter ​ ​ — ​ ​ 109 ​ Total $ 21 ​ $ 728 ​ ​ Letters of credit and surety bonds At December 31, 2023 and 2022, we had outstanding letters of credit totaling $16 million and $8 million, respectively, issued under various committed and uncommitted credit lines provided by banks to guarantee various contract bidding, performance activities and customs obligations. At December 31, 2023 and 2022, we also had outstanding surety bonds totaling $198 million and $161 million, respectively, to secure customs obligations related to the importation of our rigs and certain performance and other obligations. At December 31, 2023 and 2022, the aggregate cash collateral held by institutions to secure our letters of credit and surety bonds was $7 million. Legal proceedings Asbestos litigation One of our subsidiaries was named as a defendant, along with numerous other companies, in lawsuits arising out of the subsidiary’s manufacture and sale of heat exchangers, and involvement in the construction and refurbishment of major industrial complexes alleging bodily injury or personal injury as a result of exposure to asbestos. As of December 31, 2023, the subsidiary was a defendant in approximately 257 lawsuits with a corresponding number of plaintiffs. For many of these lawsuits, we have not been provided sufficient information from the plaintiffs to determine whether all or some of the plaintiffs have claims against the subsidiary, the basis of any such claims, or the nature of their alleged injuries. The operating assets of the subsidiary were sold in 1989. In December 2021, the subsidiary and certain insurers agreed to a settlement of outstanding disputes that provide the subsidiary with cash. An earlier settlement, achieved in September 2018, provided the subsidiary with cash and an annuity that begins making payments in 2024. Together with a coverage-in-place agreement with certain insurers and additional coverage issued by other insurers, we believe the subsidiary has sufficient resources to respond to both the current lawsuits as well as future lawsuits of a similar nature. While we cannot predict or provide assurance as to the outcome of these matters, we do not expect the ultimate liability, if any, resulting from these claims to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows. Other matters Environmental matters We have certain potential liabilities under the Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA”) and similar state acts regulating cleanup of hazardous substances at various waste disposal sites, including those described below. CERCLA is intended to expedite the remediation of hazardous substances without regard to fault. Potentially responsible parties (“PRPs”) for each site include present and former owners and operators of, transporters to and generators of the substances at the site. It is difficult to quantify the potential cost of environmental matters and remediation obligations. Liability is strict and can be joint and several. One of our subsidiaries was named as a PRP in connection with a site located in Santa Fe Springs, California, known as the Waste Disposal, Inc. site. We and other PRPs agreed, under a participation agreement with the U.S. Environmental Protection Agency (the “EPA”) and the U.S. Department of Justice, to settle our potential liabilities by remediating the site. The remedial action for the site was completed in 2006. Our share of the ongoing operating and maintenance costs has been insignificant, and we do not expect any additional potential liabilities to be material. Resolutions of other claims by the EPA, the involved state agency or PRPs are at various stages of investigation. Nevertheless, based on available information with respect to all environmental matters, including all related pending legal proceedings, asserted legal claims and known potential legal claims that are likely to be asserted, we do not expect the ultimate liability, if any, resulting from such matters, to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Equity

Equity	12 Months Ended
	Dec. 31, 2023
Equity
Equity	Note 14—Equity Share issuance Note 4—Unconsolidated Affiliates Note 7—Long-Lived Assets Note 9—Debt We maintain an at-the-market equity offering program (the “ATM Program”). We intend to use the net proceeds from our ongoing ATM Program for general corporate purposes, which may include, among other things, the repayment or refinancing of indebtedness and the funding of working capital, capital expenditures, investments and additional balance sheet liquidity. In June 2021, we entered into an equity distribution agreement with a sales agent for the offer and sale of our shares, with a maximum aggregate net offering price of up to $400 million, under the ATM Program. In August 2022, we entered into an equity distribution agreement with a sales agent for the offer and sale of our shares, with a maximum aggregate net offering price of up to $435 million, under the ATM Program. In the year ended December 31, 2023, we did not issue any shares under the ATM Program. In the years ended December 31, 2022 and 2021, we received aggregate cash proceeds of $263 million and $158 million, respectively, net of issue costs, for the aggregate sale of 61.0 million shares and 36.1 million shares, respectively, under the ATM Program. Warrants Shares held by subsidiaries

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Compensation
Share-Based Compensation	Note 15—Share-Based Compensation Overview We have a long-term incentive plan (the “Long-Term Incentive Plan”) for executives, key employees and non-employee directors under which awards can be granted in the form of restricted share units, restricted shares, stock options, stock appreciation rights and cash performance awards. Awards may be granted as service awards that are earned over a defined service period or as performance awards that are earned based on the achievement of certain market factors or performance targets or a combination of market factors and performance targets. The compensation committee of our board of directors determines the terms and conditions of the awards granted under the Long-Term Incentive Plan. At December 31, 2023, we had 115.7 million shares authorized and 31.2 million shares available to be granted under the Long-Term Incentive Plan. At December 31, 2023, the total unrecognized compensation cost related to our unvested share-based awards was $42 million, which we expect to recognize over a weighted-average period of 1.72 years. Service awards typically vest either in three a seven-year period. Performance awards are typically subject to a three-year measurement period and typically vest in one aggregate installment following the ultimate determination date. Service awards Restricted share units ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ Weighted-average ​ ​ ​ ​ ​ ​ ​ of ​ grant-date fair value ​ ​ ​ ​ ​ ​ units per unit Unvested at January 1, 2023 ​ ​ ​ ​ ​ ​ 12,047,500 ​ $ 3.25 Granted ​ ​ ​ ​ ​ ​ 3,744,049 ​ ​ 7.23 ​ Vested ​ ​ ​ ​ ​ ​ (6,200,155) ​ ​ 2.94 ​ Forfeited ​ ​ ​ ​ ​ ​ (31,386) ​ ​ 3.56 ​ Unvested at December 31, 2023 ​ ​ ​ ​ ​ ​ 9,560,008 ​ $ 5.01 ​ ​ In the year ended December 31, 2023, the service-based units that vested had an aggregate grant-date fair value of $18 million. In the years ended December 31, 2022 and 2021, we granted 6,768,943 and 6,148,361 service-based units, respectively, with a per unit weighted-average grant-date fair value of $3.60 and $3.56, respectively. In the years ended December 31, 2022 and 2021, we had 5,075,374 and 4,368,749 service-based units, respectively, that vested with an aggregate grant-date fair value of $18 million and $16 million, respectively. Stock options ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average ​ ​ ​ ​ Number ​ Weighted-average ​ remaining ​ Aggregate ​ ​ of shares ​ exercise price ​ contractual term ​ intrinsic value ​ under option per share (years) (in millions) Outstanding at January 1, 2023 ​ 4,175,520 ​ $ 10.63 ​ 4.82 ​ $ — ​ Forfeited ​ (25,017) ​ ​ 59.30 ​ ​ ​ ​ ​ ​ Expired ​ (66,574) ​ ​ 59.30 ​ ​ ​ ​ ​ ​ Outstanding at December 31, 2023 ​ 4,083,929 ​ $ 9.54 ​ 3.92 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vested and exercisable at December 31, 2023 ​ 4,083,929 ​ $ 9.54 ​ 3.92 ​ $ — ​ ​ In the years ended December 31, 2022 and 2021, the stock options that vested had an aggregate grant-date fair value of $4 million and $9 million, respectively. At December 31, 2023 and 2022, there were no outstanding unvested stock options to purchase our shares. Performance awards Restricted share units ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ Weighted-average ​ ​ ​ ​ ​ ​ ​ of ​ grant-date fair value ​ ​ ​ ​ ​ ​ units per unit Unvested at January 1, 2023 ​ ​ ​ ​ ​ ​ 6,545,369 ​ $ 3.81 ​ Granted ​ ​ ​ ​ ​ ​ 1,912,292 ​ ​ 6.74 ​ Vested ​ ​ ​ ​ ​ ​ (3,025,512) ​ ​ 3.70 ​ Unvested at December 31, 2023 ​ ​ ​ ​ ​ ​ 5,432,149 ​ $ 4.91 ​ ​ In the years ended December 31, 2023, 2022 and 2021, the performance-based units that vested had an aggregate grant-date fair value of $11 million, $5 million and $11 million, respectively. In the years ended December 31, 2022 and 2021, we granted 3,519,857 and 3,025,512 performance-based units, respectively, with a per unit weighted-average grant-date fair value of $3.91 and $3.70, respectively.

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	12 Months Ended
	Dec. 31, 2023
Supplemental Balance Sheet Information
Supplemental Balance Sheet Information	Note 16—Supplemental Balance Sheet Information Other current liabilities were comprised of the following (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Other current liabilities ​ ​ ​ ​ ​ ​ ​ Accrued employee benefits and payroll-related liabilities $ 145 ​ $ 156 ​ Accrued interest ​ ​ 146 ​ ​ 113 ​ Accrued taxes, other than income ​ ​ 47 ​ ​ 41 ​ Finance lease liability ​ ​ 43 ​ ​ 40 ​ Operating lease liabilities ​ ​ 12 ​ ​ 7 ​ Deferred revenues ​ ​ 165 ​ ​ 124 ​ Contingent liabilities ​ ​ 116 ​ ​ 58 ​ Other ​ ​ 7 ​ ​ — ​ Total other current liabilities $ 681 ​ $ 539 ​ ​ Other long-term liabilities were comprised of the following (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Other long-term liabilities ​ ​ ​ ​ ​ ​ ​ Postemployment benefit plan obligations $ 121 ​ $ 170 ​ Finance lease liability ​ ​ 276 ​ ​ 323 ​ Operating lease liabilities ​ ​ 108 ​ ​ 100 ​ Income taxes payable ​ ​ 80 ​ ​ 129 ​ Deferred revenues ​ ​ 233 ​ ​ 204 ​ Other ​ ​ 40 ​ ​ 39 ​ Total other long-term liabilities $ 858 ​ $ 965 ​ ​

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2023
Supplemental Cash Flow Information
Supplemental Cash Flow Information	Note 17—Supplemental Cash Flow Information The reconciling adjustments of our net cash provided by operating activities that were attributable to the net change in other operating assets and liabilities were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 2022 2021 Changes in other operating assets and liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Increase) decrease in accounts receivable ​ ​ $ (99) ​ $ (15) ​ $ 137 ​ Increase in other assets ​ ​ ​ ​ (98) ​ ​ (12) ​ ​ (13) ​ Increase (decrease) in accounts payable and other current liabilities ​ ​ ​ ​ 135 ​ ​ 8 ​ ​ (52) ​ Decrease in other long-term liabilities ​ ​ ​ ​ (7) ​ ​ (2) ​ ​ (3) ​ Change in income taxes receivable / payable, net ​ ​ ​ ​ (36) ​ ​ (42) ​ ​ (17) ​ Change in receivables from / payables to affiliates, net ​ ​ ​ ​ (8) ​ ​ (12) ​ ​ (15) ​ ​ ​ ​ $ (113) ​ $ (75) ​ $ 37 ​ ​ Additional cash flow information was as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 2022 2021 Certain cash operating activities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash payments for interest ​ ​ $ 408 ​ $ 355 ​ $ 429 ​ Cash payments for income taxes ​ ​ ​ ​ 41 ​ ​ 66 ​ ​ 57 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-cash investing and financing activities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital additions accrued at end of period ​ (a) ​ $ 36 ​ $ 31 ​ $ 28 ​ Capital additions acquired in exchange for debt ​ (b) ​ ​ — ​ ​ 382 ​ ​ — ​ Acquisition of outstanding ownership interests in exchange for shares ​ (c) ​ ​ 99 ​ ​ — ​ ​ — ​ Debt investment exchanged for equity ownership interests ​ (d) ​ ​ 37 ​ ​ — ​ ​ — ​ Finance lease installments settled with credits issued to customer ​ (e) ​ ​ 44 ​ ​ 41 ​ ​ — ​ Shares issued in exchanges of exchangeable bonds ​ (f) ​ ​ 434 ​ ​ — ​ ​ — ​ Debt and warrants issued in exchange transactions ​ (g) ​ ​ — ​ ​ 110 ​ ​ 260 ​ (a) Additions to property and equipment for which we had accrued a corresponding liability in accounts payable at the end of the period. See Note 7—Long-Lived Assets . (b) In the year ended December 31, 2022, we borrowed an aggregate principal amount of $439 million under the Shipyard Loans to satisfy a portion of the final milestone payments due upon delivery of Deepwater Atlas and Deepwater Titan and recorded the initial carrying amount, net of imputed interest, with a corresponding entry to construction in progress, recorded in property and equipment. See Note 7—Long-Lived Assets and Note 9—Debt . (c) In September 2023, we issued 11.9 million Transocean Ltd. shares to acquire the outstanding ownership interests in Liquila. See Note 4—Unconsolidated Affiliates , Note 7—Long-Lived Assets and Note 14—Equity . (d) In September 2023, we agreed to exchange borrowings due to us under a financing arrangement with Orion for additional equity ownership interests in Orion. See Note 4—Unconsolidated Affiliates . (e) In the years ended December 31, 2023 and 2022, we agreed to settle installments due to the lessor under our finance lease by issuing corresponding credits to our customer for amounts due to us under the drilling contract. See Note 8—Leases . (f) In the year ended December 31, 2023, we issued 65.1 million Transocean Ltd. shares to certain holders that elected to exchange the 2.50% Senior Guaranteed Exchangeable Bonds, the 4.00% Senior Guaranteed Exchangeable Bonds and the 4.625% Senior Guaranteed Exchangeable Bonds. See Note 9—Debt and Note 14—Equity . (g) In the year ended December 31, 2022, in connection with the 2022 Private Exchange, we issued $112 million aggregate principal amount of the 4.625% Senior Guaranteed Exchangeable Bonds with an estimated fair value of $105 million and 6.7 million warrants to purchase Transocean Ltd. shares with an estimated fair value of $5 million. In the year ended December 31, 2021, in connection with the 2021 Private Exchange, we issued $294 million aggregate principal amount of the 4.00% Senior Guaranteed Exchangeable Bonds with an estimated fair value of $260 million. See Note 9—Debt and Note 14—Equity .

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2023
Financial Instruments
Financial Instruments	Note 18—Financial Instruments Overview ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ Carrying ​ Fair ​ Carrying ​ Fair ​ amount value amount value Cash and cash equivalents $ 762 ​ $ 762 ​ $ 683 ​ $ 683 ​ Restricted cash and cash equivalents ​ ​ 233 ​ ​ 233 ​ ​ 308 ​ ​ 308 ​ Long-term loans receivable from unconsolidated affiliates ​ ​ 6 ​ ​ 6 ​ ​ 41 ​ ​ 43 ​ Total debt ​ ​ 7,413 ​ ​ 7,308 ​ ​ 7,347 ​ ​ 6,412 ​ ​ Cash and cash equivalents Restricted cash and cash equivalents Long-term loans receivable from unconsolidated affiliates Total debt Note 9—Debt

Risk Concentration

Risk Concentration	12 Months Ended
	Dec. 31, 2023
Risk Concentration
Risk Concentration	Note 19—Risk Concentration Interest rate risk Equity price risk Currency exchange rate risk Credit risk Labor agreements

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Significant Accounting Policies
Accounting estimates	Accounting estimates
Fair value measurements	Fair value measurements
Consolidation	Consolidation Note 4—Unconsolidated Affiliates Note 14—Equity
Functional currency	Functional currency
Revenues and related pre-operating costs	Revenues and related pre-operating costs over the contract period unless otherwise constrained. We recognize revenues from contract terminations as we fulfill our obligations and all contingencies have been resolved. We apply the optional exemption that permits us to exclude disclosure of the estimated transaction price related to the variable portion of unsatisfied performance obligations at the end of the reporting period, as our transaction price is typically based on a single performance obligation consisting of a series of distinct hourly, or more frequent, periods, the variability of which will be resolved at the time of the future services. To obtain contracts with our customers, we incur pre-operating costs to prepare a rig for contract and mobilize a rig to the drilling location. We defer such pre-operating contract preparation and mobilization costs for recognition in operating and maintenance costs over the estimated contract period on a straight-line basis, consistent with the general pace of activity. See Note 5—Revenues
Income taxes	Income taxes We maintain liabilities for estimated tax exposures in our jurisdictions of operation, and we recognize the provisions and benefits resulting from changes to those liabilities in our income tax expense or benefit along with related interest and penalties. Income tax exposure items include potential challenges to permanent establishment positions, intercompany pricing, disposition transactions, and withholding tax rates and their applicability. These tax exposures are resolved primarily through the settlement of audits within these tax jurisdictions or by judicial means, but can also be affected by changes in applicable tax law or other factors, which could cause us to revise past estimates. We measure deferred tax assets and liabilities using enacted tax rates that will apply in the years in which the deferred tax assets and liabilities are expected to be recovered or paid. In evaluating our ability to realize deferred tax assets, we consider all available positive and negative evidence, including projected future taxable income and the existence of cumulative losses in recent years. We record a valuation allowance for deferred tax assets when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. For example, we may record a valuation allowance for deferred tax assets resulting from net operating losses incurred during the year in certain jurisdictions for which the benefit of the losses will not be realized or for foreign tax credit carryforwards that may expire prior to their utilization. See Note 11—Income Taxes
Cash and cash equivalents	Cash and cash equivalents
Restricted cash and cash equivalents	Restricted cash and cash equivalents Note 9—Debt
Materials and supplies	Materials and supplies
Property and equipment	Property and equipment We capitalize expenditures for newbuilds, renewals, replacements and improvements, including capitalized interest, if applicable, and we recognize the expense for maintenance and repair costs as incurred. For newbuild construction projects, we also capitalize the initial preparation, mobilization and commissioning costs incurred until the drilling unit is placed into service. Upon sale or other disposition of an asset, we recognize a net gain or loss on disposal of the asset, which is measured as the difference between the net carrying amount of the asset and the net proceeds received. We compute depreciation using the straight-line method after allowing for salvage values. The estimated original useful life of our drilling units is 35 years, our buildings and improvements range from three four
Long-lived asset impairment	Long lived asset impairment ultra-deepwater floaters and harsh environment floaters. When an impairment of one or more of our asset groups is indicated, we measure an impairment as the amount by which the carrying amount of the asset group exceeds its estimated fair value. We measure the fair values of our asset groups by applying a variety of valuation methods, incorporating a combination of income, market and cost approaches, using projected discounted cash flows and estimates of the exchange price that would be received for the assets in the principal or most advantageous market for the assets in an orderly transaction between market participants as of the measurement date. For an asset classified as held for sale, we consider the asset to be impaired to the extent its carrying amount exceeds its estimated fair value less cost to sell. See Note 7—Long-Lived Assets
Equity investments and impairment	Equity investments and impairment Note 4—Unconsolidated Affiliates
Pension and other postemployment benefit plans	Pension and other postemployment benefit plans We measure the actuarially determined obligations and related costs for our defined benefit pension and other postemployment benefit plans, retiree life insurance and medical benefits, by applying assumptions, the most significant of which include long-term rate of return on plan assets, discount rates and mortality rates. For the long-term rate of return, we develop our assumptions regarding the expected rate of return on plan assets based on historical experience and projected long-term investment returns, and we weight the assumptions based on each plan’s asset allocation. For the discount rate, we base our assumptions on a yield curve approach using Aa-rated corporate bonds and the expected timing of future benefit payments. At December 31, 2023 and 2022, the funded status of our pension and other postemployment benefit plans represented an aggregate liability of $125 million and $174 million, respectively, and an aggregate asset of $31 million and $44 million, respectively. See Note 10—Postemployment Benefit Plans
Share-based compensation	Share based compensation Note 15—ShareBased Compensation
Contingencies	Contingencies

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2023
Revenues
Schedule of revenue disaggregation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ ​ Year ended December 31, 2022 ​ ​ Year ended December 31, 2021 ​ ​ ​ Ultra- Harsh ​ ​ ​ ​ Ultra- ​ Harsh ​ ​ ​ ​ Ultra- ​ Harsh ​ ​ ​ ​ ​ ​ deepwater environment ​ ​ ​ ​ deepwater ​ environment ​ ​ ​ ​ deepwater ​ environment ​ ​ ​ ​ ​ floaters floaters ​ Total ​ ​ floaters ​ floaters ​ Total ​ ​ floaters ​ floaters ​ Total ​ U.S. $ 1,433 ​ $ — ​ $ 1,433 ​ ​ $ 1,135 ​ $ — ​ $ 1,135 ​ ​ $ 1,096 ​ $ 2 ​ $ 1,098 ​ Norway ​ ​ — ​ ​ 603 ​ ​ 603 ​ ​ ​ — ​ ​ 835 ​ ​ 835 ​ ​ ​ — ​ ​ 790 ​ ​ 790 ​ Brazil ​ ​ 298 ​ ​ — ​ ​ 298 ​ ​ ​ 240 ​ ​ — ​ ​ 240 ​ ​ ​ 237 ​ ​ — ​ ​ 237 ​ Other countries (a) ​ ​ 341 ​ ​ 157 ​ ​ 498 ​ ​ ​ 333 ​ ​ 32 ​ ​ 365 ​ ​ ​ 387 ​ ​ 44 ​ ​ 431 ​ Total contract drilling revenues $ 2,072 ​ $ 760 ​ $ 2,832 ​ ​ $ 1,708 ​ $ 867 ​ $ 2,575 ​ ​ $ 1,720 ​ $ 836 ​ $ 2,556 ​ (a) The aggregate contract drilling revenues earned in other countries that individually represented less than 10 percent of total contract drilling revenues.
Schedule of contract balances and changes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2023 2022 Deferred contract revenues, recorded in other current liabilities $ 165 ​ $ 124 ​ Deferred contract revenues, recorded in other long-term liabilities ​ ​ 233 ​ ​ 204 ​ Total contract liabilities $ 398 ​ $ 328 ​ Significant changes in contract liabilities were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended ​ ​ ​ December 31, ​ ​ 2023 2022 Total contract liabilities, beginning of period ​ $ 328 ​ $ 348 ​ Decrease due to recognition of revenues for goods and services ​ ​ (189) ​ ​ (119) ​ Increase due to goods and services transferred over time ​ ​ 259 ​ ​ 99 ​ Total contract liabilities, end of period ​ $ 398 ​ $ 328 ​

Contract Intangible Assets (Tab

Contract Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2023
Contract Intangible Assets
Schedule of contract intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ ​ Gross ​ ​ ​ ​ Net ​ Gross ​ ​ ​ ​ Net ​ ​ carrying ​ Accumulated ​ carrying ​ carrying ​ Accumulated ​ carrying ​ amount ​ amortization ​ amount amount amortization amount Drilling contract intangible assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period $ 907 ​ $ (851) ​ $ 56 ​ $ 907 ​ $ (734) $ 173 ​ Amortization ​ ​ — ​ ​ (52) ​ ​ (52) ​ ​ — ​ ​ (117) ​ ​ (117) ​ Balance, end of period $ 907 ​ $ (903) ​ $ 4 ​ $ 907 ​ $ (851) $ 56 ​

Long-Lived Assets (Tables)

Long-Lived Assets (Tables)	12 Months Ended
	Dec. 31, 2023
Long-Lived Assets
Schedule of long-lived assets of the entity's continuing operations by country	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Long-lived assets ​ ​ ​ ​ ​ ​ ​ U.S. $ 7,472 ​ $ 6,514 ​ Greece ​ ​ 2,652 ​ ​ 3,022 ​ Norway ​ ​ 2,103 ​ ​ 3,255 ​ Other countries (a) ​ ​ 5,200 ​ ​ 5,171 ​ Total long-lived assets $ 17,427 ​ $ 17,962 ​ (a) The aggregate carrying amount of long-lived assets located in other countries that individually represented less than 10 percent of total long-lived assets.
Changes in our construction work in progress, including capital expenditures and capitalized interest	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 Construction work in progress, beginning of period ​ $ 1,195 ​ $ 1,017 ​ $ 828 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital expenditures ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ 331 ​ ​ 669 ​ ​ 174 ​ Other equipment and construction projects ​ ​ 96 ​ ​ 48 ​ ​ 34 ​ Total capital expenditures ​ ​ 427 ​ ​ 717 ​ ​ 208 ​ Non-cash capital additions acquired in exchange for issuance of shares ​ ​ 126 ​ ​ — ​ ​ — ​ Non-cash capital additions financed under Shipyard Loans ​ ​ — ​ ​ 382 ​ ​ — ​ Changes in accrued capital additions ​ ​ 5 ​ ​ 3 ​ ​ 13 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Property and equipment placed into service ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ (1,157) ​ ​ (882) ​ ​ — ​ Other equipment and construction projects ​ ​ (74) ​ ​ (42) ​ ​ (32) ​ Construction work in progress, end of period ​ $ 522 ​ $ 1,195 ​ $ 1,017 ​

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases
Schedule of lease costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ Lease costs ​ 2023 2022 2021 ​ Short-term lease costs ​ $ 4 ​ $ 14 ​ $ 17 ​ Operating lease costs ​ ​ 14 ​ ​ 12 ​ ​ 12 ​ Finance lease costs, amortization of right-of-use asset ​ ​ 20 ​ ​ 20 ​ ​ 20 ​ Finance lease costs, interest on lease liability ​ ​ 27 ​ ​ 30 ​ ​ 33 ​ Total lease costs ​ $ 65 ​ $ 76 ​ $ 82 ​
Schedule of lease cash flow information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 2022 2021 ​ Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 17 ​ $ 14 ​ $ 13 ​ Operating cash flows from finance lease ​ ​ — ​ ​ 8 ​ ​ 37 ​ Financing cash flows from finance lease ​ ​ — ​ ​ 3 ​ ​ 33 ​
Schedule of future minimum payments on operating leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Finance ​ ​ ​ ​ ​ ​ leases ​ lease ​ Years ending December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ ​ ​ $ 19 ​ $ 65 ​ 2025 ​ ​ ​ ​ ​ 19 ​ ​ 70 ​ 2026 ​ ​ ​ ​ ​ 18 ​ ​ 71 ​ 2027 ​ ​ ​ ​ ​ 15 ​ ​ 70 ​ 2028 ​ ​ ​ ​ ​ 13 ​ ​ 71 ​ Thereafter ​ ​ ​ ​ ​ 89 ​ ​ 47 ​ Total future minimum rental payment ​ ​ ​ ​ ​ 173 ​ ​ 394 ​ Less amount representing imputed interest ​ ​ ​ ​ ​ (53) ​ ​ (75) ​ Present value of future minimum rental payments ​ ​ ​ ​ ​ 120 ​ ​ 319 ​ Current portion, recorded in other current liabilities ​ ​ ​ ​ ​ 12 ​ ​ 43 ​ Long-term lease liabilities, recorded in other long-term liabilities ​ ​ ​ ​ $ 108 ​ $ 276 ​ ​
Schedule of future minimum payments on finance leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Finance ​ ​ ​ ​ ​ ​ leases ​ lease ​ Years ending December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ ​ ​ $ 19 ​ $ 65 ​ 2025 ​ ​ ​ ​ ​ 19 ​ ​ 70 ​ 2026 ​ ​ ​ ​ ​ 18 ​ ​ 71 ​ 2027 ​ ​ ​ ​ ​ 15 ​ ​ 70 ​ 2028 ​ ​ ​ ​ ​ 13 ​ ​ 71 ​ Thereafter ​ ​ ​ ​ ​ 89 ​ ​ 47 ​ Total future minimum rental payment ​ ​ ​ ​ ​ 173 ​ ​ 394 ​ Less amount representing imputed interest ​ ​ ​ ​ ​ (53) ​ ​ (75) ​ Present value of future minimum rental payments ​ ​ ​ ​ ​ 120 ​ ​ 319 ​ Current portion, recorded in other current liabilities ​ ​ ​ ​ ​ 12 ​ ​ 43 ​ Long-term lease liabilities, recorded in other long-term liabilities ​ ​ ​ ​ $ 108 ​ $ 276 ​ ​

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2023
Debt
Schedule of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal amount ​ ​ Carrying amount ​ ​ ​ ​ December 31, ​ December 31, ​ December 31, ​ December 31, ​ ​ 2023 2022 2023 2022 0.50% Exchangeable Senior Bonds due January 2023 ​ (a) ​ $ — ​ $ 49 ​ ​ $ — ​ $ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ (b) ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ (b) ​ ​ — ​ ​ 352 ​ ​ ​ — ​ ​ 350 ​ 7.75% Senior Secured Notes due October 2024 ​ (b) ​ ​ — ​ ​ 240 ​ ​ ​ — ​ ​ 238 ​ 6.25% Senior Secured Notes due December 2024 ​ (b) ​ ​ — ​ ​ 250 ​ ​ ​ — ​ ​ 248 ​ 6.125% Senior Secured Notes due August 2025 ​ (b) ​ ​ — ​ ​ 336 ​ ​ ​ — ​ ​ 332 ​ 7.25% Senior Notes due November 2025 ​ (c) ​ ​ 354 ​ ​ 354 ​ ​ ​ 352 ​ ​ 351 ​ 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ (d) ​ ​ 234 ​ ​ 294 ​ ​ ​ 221 ​ ​ 271 ​ 7.50% Senior Notes due January 2026 ​ (c) ​ ​ 569 ​ ​ 569 ​ ​ ​ 567 ​ ​ 566 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ (d) ​ ​ — ​ ​ 238 ​ ​ ​ — ​ ​ 265 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ (d) ​ ​ 687 ​ ​ 687 ​ ​ ​ 938 ​ ​ 1,008 ​ 6.875% Senior Secured Notes due February 2027 ​ (b) ​ ​ 413 ​ ​ 482 ​ ​ ​ 409 ​ ​ 477 ​ 8.00% Senior Notes due February 2027 ​ (c) ​ ​ 612 ​ ​ 612 ​ ​ ​ 609 ​ ​ 608 ​ 7.45% Notes due April 2027 ​ (a) ​ ​ 52 ​ ​ 52 ​ ​ ​ 52 ​ ​ 52 ​ 8.00% Debentures due April 2027 ​ (a) ​ ​ 22 ​ ​ 22 ​ ​ ​ 22 ​ ​ 22 ​ 4.50% Shipyard Loans due September 2027 ​ (e) ​ ​ 420 ​ ​ 439 ​ ​ ​ 384 ​ ​ 389 ​ 8.375% Senior Secured Notes due February 2028 ​ (b) ​ ​ 525 ​ ​ — ​ ​ ​ 518 ​ ​ — ​ 7.00% Notes due June 2028 ​ (e) ​ ​ 261 ​ ​ 261 ​ ​ ​ 264 ​ ​ 264 ​ 8.00% Senior Secured Notes due September 2028 ​ (b) ​ ​ 325 ​ ​ — ​ ​ ​ 321 ​ ​ — ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ (c) ​ ​ 259 ​ ​ 300 ​ ​ ​ 486 ​ ​ 440 ​ 8.75% Senior Secured Notes due February 2030 ​ (f) ​ ​ 1,116 ​ ​ — ​ ​ ​ 1,094 ​ ​ — ​ 7.50% Notes due April 2031 ​ (a) ​ ​ 396 ​ ​ 396 ​ ​ ​ 395 ​ ​ 394 ​ 6.80% Senior Notes due March 2038 ​ (a) ​ ​ 610 ​ ​ 610 ​ ​ ​ 605 ​ ​ 605 ​ 7.35% Senior Notes due December 2041 ​ (a) ​ ​ 177 ​ ​ 177 ​ ​ ​ 176 ​ ​ 176 ​ Total debt ​ ​ ​ ​ 7,032 ​ ​ 6,963 ​ ​ ​ 7,413 ​ ​ 7,347 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less debt due within one year ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 0.50% Exchangeable Senior Bonds due January 2023 ​ (a) ​ ​ — ​ ​ 49 ​ ​ ​ — ​ ​ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ (b) ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ (b) ​ ​ — ​ ​ 83 ​ ​ ​ — ​ ​ 81 ​ 7.75% Senior Secured Notes due October 2024 ​ (b) ​ ​ — ​ ​ 60 ​ ​ ​ — ​ ​ 59 ​ 6.25% Senior Secured Notes due December 2024 ​ (b) ​ ​ — ​ ​ 62 ​ ​ ​ — ​ ​ 61 ​ 6.125% Senior Secured Notes due August 2025 ​ (b) ​ ​ — ​ ​ 66 ​ ​ ​ — ​ ​ 64 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ (d) ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ 6 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ (d) ​ ​ — ​ ​ — ​ ​ ​ 71 ​ ​ 70 ​ 6.875% Senior Secured Notes due February 2027 ​ (b) ​ ​ 83 ​ ​ 69 ​ ​ ​ 81 ​ ​ 67 ​ 4.50% Shipyard Loans due September 2027 ​ (e) ​ ​ 90 ​ ​ 20 ​ ​ ​ 75 ​ ​ 20 ​ 8.00% Senior Secured Notes due September 2028 ​ (b) ​ ​ 30 ​ ​ — ​ ​ ​ 30 ​ ​ — ​ 8.75% Senior Secured Notes due February 2030 ​ (f) ​ ​ 117 ​ ​ — ​ ​ ​ 113 ​ ​ — ​ Total debt due within one year ​ ​ ​ ​ 320 ​ ​ 652 ​ ​ ​ 370 ​ ​ 719 ​ Total long-term debt ​ $ 6,712 ​ $ 6,311 ​ $ 7,043 ​ $ 6,628 ​ (a) Transocean Inc., a wholly owned direct subsidiary of Transocean Ltd., is the issuer of the notes and debentures (the “Legacy Guaranteed Notes”). The Legacy Guaranteed Notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. (b) Each subsidiary issuer of the respective unregistered notes is a wholly owned indirect subsidiary of Transocean Inc. The senior secured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd., Transocean Inc. and, in each case, the owner of the respective collateral rig or rigs. (c) Transocean Inc. is the issuer of the unregistered notes (collectively, the “Priority Guaranteed Notes”). The guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean Inc. and rank equal in right of payment of all our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Legacy Guaranteed Notes, the 4.50% shipyard loans due September 2027 (each, a “Shipyard Loan”, and together, the “Shipyard Loans”) and the 7.00% notes due June 2028 and structurally subordinate to the Senior Priority Guaranteed Notes, as defined below, to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (d) Transocean Inc. is the issuer of the unregistered notes (together, the “Senior Priority Guaranteed Notes”). The priority guaranteed senior unsecured notes are fully and unconditionally, jointly and severally, guaranteed by Transocean Ltd. and certain wholly owned indirect subsidiaries of Transocean Inc. and rank equal in right of payment of all of our existing and future unsecured unsubordinated obligations. Such notes are structurally senior to the Priority Guaranteed Notes to the extent of the value of the assets of the subsidiaries guaranteeing the notes. (e) The subsidiary borrowers under the Shipyard Loans and the subsidiary issuer of the registered notes are wholly owned indirect subsidiaries of Transocean Inc. The loans and notes are fully and unconditionally guaranteed by Transocean Inc. (f) Transocean Inc. is the issuer of the unregistered notes. The senior secured notes are fully and unconditionally guaranteed on an unsecured basis by Transocean Ltd. and on a limited senior secured basis by each of the wholly owned subsidiary owners of the collateral rigs.
Scheduled maturities of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Other Total ​ installments installments installments Years ending December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ $ 320 ​ $ 71 ​ $ 391 ​ 2025 ​ ​ 1,068 ​ ​ 72 ​ ​ 1,140 ​ 2026 ​ ​ 1,110 ​ ​ 72 ​ ​ 1,182 ​ 2027 ​ ​ 1,900 ​ ​ 36 ​ ​ 1,936 ​ 2028 ​ ​ 664 ​ ​ — ​ ​ 664 ​ Thereafter ​ ​ 1,970 ​ ​ — ​ ​ 1,970 ​ Total installments ​ $ 7,032 ​ $ 251 ​ ​ 7,283 ​ Total unamortized debt-related balances, net ​ ​ ​ ​ ​ ​ ​ ​ (220) ​ Bifurcated compound exchange feature, at estimated fair value ​ ​ ​ ​ ​ ​ ​ ​ 350 ​ Total carrying amount of debt ​ ​ ​ ​ ​ ​ ​ $ 7,413 ​
Schedule of interest expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Contractual interest ​ $ 24 ​ $ 16 ​ $ 11 ​ Amortization ​ ​ 19 ​ ​ 9 ​ ​ 5 ​ Bifurcated compound exchange feature ​ ​ 127 ​ ​ 157 ​ ​ — ​ Total ​ $ 170 ​ $ 182 ​ $ 16 ​
Schedule of debt retirements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ ​ 2022 ​ ​ 2021 ​ ​ Redeemed ​ ​ Redeemed ​ Exchanged ​ Total ​ Redeemed Exchanged Total 5.52% Senior Secured Notes due May 2022 ​ $ — ​ ​ $ 18 ​ $ — ​ $ 18 ​ ​ $ — ​ $ — ​ $ — ​ 3.80% Senior Notes due October 2022 ​ ​ — ​ ​ ​ 27 ​ ​ — ​ ​ 27 ​ ​ ​ — ​ ​ — ​ ​ — ​ 0.50% Exchangeable Senior Bonds due January 2023 ​ ​ — ​ ​ ​ 18 ​ ​ 73 ​ ​ 91 ​ ​ ​ — ​ ​ 323 ​ ​ 323 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ 243 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 11 ​ ​ — ​ ​ 11 ​ 5.875% Senior Secured Notes due January 2024 ​ ​ 311 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ 68 ​ ​ — ​ ​ 68 ​ 7.75% Senior Secured Notes due October 2024 ​ ​ 240 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ — ​ ​ — ​ 6.25% Senior Secured Notes due December 2024 ​ ​ 250 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ — ​ ​ — ​ 6.125% Senior Secured Notes due August 2025 ​ ​ 336 ​ ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ — ​ ​ — ​ ​ — ​ 7.25% Senior Notes due November 2025 ​ ​ — ​ ​ ​ 14 ​ ​ 43 ​ ​ 57 ​ ​ ​ — ​ ​ — ​ ​ — ​ Aggregate principal amount of debt retired ​ $ 1,380 ​ ​ $ 77 ​ $ 116 ​ $ 193 ​ ​ $ 79 ​ $ 323 ​ $ 402 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate cash payment ​ $ 1,402 ​ ​ $ 75 ​ $ — ​ $ 75 ​ ​ $ 79 ​ $ 11 ​ $ 90 ​ Aggregate principal amount of debt issued in exchanges ​ $ — ​ ​ $ — ​ $ 112 ​ $ 112 ​ ​ $ — ​ $ 294 ​ $ 294 ​ Aggregate fair value of warrants issued in exchanges ​ $ — ​ ​ $ — ​ $ 5 ​ $ 5 ​ ​ $ — ​ $ — ​ $ — ​ Aggregate net gain (loss) ​ $ (32) ​ ​ $ 2 ​ $ 6 ​ $ 8 ​ ​ $ — ​ $ 51 ​ $ 51 ​
Exchanged
Debt
Schedule of debt	Exchange terms ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Implied ​ ​ ​ ​ ​ Exchange ​ exchange Shares ​ ​ rate ​ price issuable 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ 190.4762 ​ $ 5.25 ​ ​ 44.5 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ 290.6618 ​ $ 3.44 ​ ​ 75.3 ​ Effective interest rates and fair values ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective Fair ​ ​ ​ ​ ​ interest rate value 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ ​ ​ ​ 6.9% ​ $ 341 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ ​ ​ ​ 18.3% ​ $ 567 ​

Postemployment Benefit Plans (T

Postemployment Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2023
Postemployment Benefit Plans
Schedule of net periodic benefit costs before tax	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ Year ended December 31, 2021 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ U.S. ​ Non-U.S. ​ OPEB ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Plans Plans Plans Total Net periodic benefit costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest cost ​ $ 65 ​ $ 9 ​ $ — ​ $ 74 ​ $ 50 ​ $ 6 ​ $ — ​ $ 56 ​ $ 47 ​ $ 6 ​ $ — ​ $ 53 ​ Expected return on plan assets ​ ​ (84) ​ ​ (11) ​ ​ — ​ ​ (95) ​ ​ (65) ​ ​ (7) ​ ​ — ​ ​ (72) ​ ​ (66) ​ ​ (13) ​ ​ — ​ ​ (79) ​ Settlements and curtailments ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (2) ​ ​ — ​ ​ (2) ​ Actuarial loss, net ​ ​ — ​ ​ 2 ​ ​ — ​ ​ 2 ​ ​ 5 ​ ​ — ​ ​ — ​ ​ 5 ​ ​ 11 ​ ​ 1 ​ ​ — ​ ​ 12 ​ Prior service gain, net ​ ​ — ​ ​ — ​ ​ (2) ​ ​ (2) ​ ​ — ​ ​ — ​ ​ (2) ​ ​ (2) ​ ​ — ​ ​ — ​ ​ (2) ​ ​ (2) ​ Net periodic benefit costs (income) ​ $ (19) ​ $ — ​ $ (2) ​ $ (21) ​ $ (10) ​ $ (1) ​ $ (2) ​ $ (13) ​ $ (8) ​ $ (8) ​ $ (2) ​ $ (18) ​
Schedule of weighted-average assumptions	Net periodic benefit costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ Year ended December 31, 2021 ​ ​ U.S. ​ U.K. ​ OPEB ​ U.S. ​ U.K. ​ OPEB ​ U.S. ​ Non-U.S. OPEB ​ ​ Plans Plan Plans Plans Plan Plans Plans Plans Plans ​ Discount rate ​ 5.06 % 4.80 % 4.92 % 2.92 % 1.90 % 1.83 % 2.60 % 1.50 % 1.21 % Expected rate of return ​ 6.41 % 5.00 % na ​ 4.81 % 2.00 % na ​ 5.51 % 3.20 % na ​ “na” means not applicable. Funded status ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ ​ ​ ​ ​ Plans Plan Plans Plans Plan Plans Discount rate ​ ​ ​ ​ ​ ​ ​ 4.88 % 4.50 % 4.80 % 5.06 % 4.80 % 4.92 % Expected long-term rate of return ​ ​ ​ ​ ​ ​ ​ 6.80 % 5.10 % na ​ 6.41 % 5.00 % na ​ “na” means not applicable.
Schedule of changes in funded status, balance sheet classifications and accumulated benefit obligations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2023 ​ Year ended December 31, 2022 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Change in projected benefit obligation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Projected benefit obligation, beginning of period $ 1,307 ​ $ 188 ​ $ 10 ​ $ 1,505 ​ $ 1,724 ​ $ 348 ​ $ 13 ​ $ 2,085 ​ Actuarial (gain) loss, net ​ ​ 32 ​ ​ 11 ​ ​ — ​ ​ 43 ​ ​ (391) ​ ​ (119) ​ ​ (1) ​ ​ (511) ​ Interest cost ​ ​ 65 ​ ​ 9 ​ ​ — ​ ​ 74 ​ ​ 50 ​ ​ 6 ​ ​ — ​ ​ 56 ​ Currency exchange rate (gain) loss ​ ​ — ​ ​ 11 ​ ​ — ​ ​ 11 ​ ​ — ​ ​ (37) ​ ​ — ​ ​ (37) ​ Benefits paid ​ ​ (76) ​ ​ (11) ​ ​ (2) ​ ​ (89) ​ ​ (76) ​ ​ (10) ​ ​ (2) ​ ​ (88) ​ Projected benefit obligation, end of period ​ ​ 1,328 ​ ​ 208 ​ ​ 8 ​ ​ 1,544 ​ ​ 1,307 ​ ​ 188 ​ ​ 10 ​ ​ 1,505 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in plan assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value of plan assets, beginning of period ​ ​ 1,143 ​ ​ 232 ​ ​ — ​ ​ 1,375 ​ ​ 1,621 ​ ​ 434 ​ ​ — ​ ​ 2,055 ​ Actual return (loss) on plan assets ​ ​ 138 ​ ​ 6 ​ ​ — ​ ​ 144 ​ ​ (403) ​ ​ (147) ​ ​ — ​ ​ (550) ​ Currency exchange rate gain (loss) ​ ​ — ​ ​ 12 ​ ​ — ​ ​ 12 ​ ​ — ​ ​ (45) ​ ​ — ​ ​ (45) ​ Employer contributions ​ ​ 6 ​ ​ — ​ ​ 2 ​ ​ 8 ​ ​ 1 ​ ​ — ​ ​ 2 ​ ​ 3 ​ Benefits paid ​ ​ (76) ​ ​ (11) ​ ​ (2) ​ ​ (89) ​ ​ (76) ​ ​ (10) ​ ​ (2) ​ ​ (88) ​ Fair value of plan assets, end of period ​ ​ 1,211 ​ ​ 239 ​ ​ — ​ ​ 1,450 ​ ​ 1,143 ​ ​ 232 ​ ​ — ​ ​ 1,375 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Funded status asset (liability), end of period $ (117) ​ $ 31 ​ $ (8) ​ $ (94) ​ $ (164) ​ $ 44 ​ $ (10) ​ $ (130) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance sheet classification, end of period: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pension asset, non-current $ — ​ $ 31 ​ $ — ​ $ 31 ​ $ — ​ $ 44 ​ $ — ​ $ 44 ​ Pension liability, current ​ ​ (1) ​ ​ — ​ ​ (3) ​ ​ (4) ​ ​ (1) ​ ​ — ​ ​ (3) ​ ​ (4) ​ Pension liability, non-current ​ ​ (116) ​ ​ — ​ ​ (5) ​ ​ (121) ​ ​ (163) ​ ​ — ​ ​ (7) ​ ​ (170) ​ Accumulated other comprehensive loss (income), before taxes ​ ​ 144 ​ ​ 90 ​ ​ (6) ​ ​ 228 ​ ​ 166 ​ ​ 76 ​ ​ (8) ​ ​ 234 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated benefit obligation, end of period ​ $ 1,328 ​ $ 208 ​ $ 8 ​ $ 1,544 ​ $ 1,307 ​ $ 188 ​ $ 10 ​ $ 1,505 ​
Schedule of projected benefit obligation in excess of plan assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Projected benefit obligation / accumulated benefit obligation $ 1,328 ​ $ — ​ $ 8 ​ $ 1,336 ​ $ 1,307 ​ $ — ​ $ 10 ​ $ 1,317 ​ Fair value of plan assets ​ ​ 1,211 ​ ​ — ​ ​ — ​ ​ 1,211 ​ ​ 1,143 ​ ​ — ​ ​ — ​ ​ 1,143 ​
Schedule of unrecognized accumulated other comprehensive loss (income)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Plans Plan Plans Total Actuarial (gain) loss, net $ 144 ​ $ 88 ​ $ (1) ​ $ 231 ​ $ 166 ​ $ 74 ​ $ (1) ​ $ 239 ​ Prior service cost (credit), net ​ ​ — ​ ​ 2 ​ ​ (5) ​ ​ (3) ​ ​ — ​ ​ 2 ​ ​ (7) ​ ​ (5) ​ Accumulated other comprehensive loss (income), before taxes $ 144 ​ $ 90 ​ $ (6) ​ $ 228 ​ $ 166 ​ $ 76 ​ $ (8) ​ $ 234 ​
Schedule of allocations of plan assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ Target allocation ​ Actual allocation ​ Target allocation ​ Actual allocation ​ ​ U.S. ​ U.K. ​ U.S. ​ U.K. ​ U.S. ​ U.K. ​ U.S. ​ U.K. ​ Plans Plan Plans Plan Plans Plan Plans Plan Equity securities ​ 38 % 20 % 37 % 21 % 38 % 20 % 38 % 24 % Fixed income securities ​ 62 % 73 % 62 % 72 % 62 % 80 % 61 % 74 % Other investments ​ — % 7 % 1 % 7 % — ​ — % 1 ​ 2 % Total ​ 100 % 100 % 100 % 100 % 100 % 100 % 100 % 100 %
Schedule of investments for the funded defined benefit plans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ Significant observable inputs ​ Significant other observable inputs ​ Total ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. equity funds $ 316 ​ $ — ​ $ 316 ​ $ — ​ $ — ​ $ — ​ $ 316 ​ $ — ​ $ 316 ​ Non-U.S. equity funds ​ ​ 139 ​ ​ — ​ ​ 139 ​ ​ — ​ ​ 51 ​ ​ 51 ​ ​ 139 ​ ​ 51 ​ ​ 190 ​ Bond funds ​ ​ 746 ​ ​ — ​ ​ 746 ​ ​ 4 ​ ​ 171 ​ ​ 175 ​ ​ 750 ​ ​ 171 ​ ​ 921 ​ Total mutual funds ​ ​ 1,201 ​ ​ — ​ ​ 1,201 ​ ​ 4 ​ ​ 222 ​ ​ 226 ​ ​ 1,205 ​ ​ 222 ​ ​ 1,427 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and money market funds ​ ​ 6 ​ ​ 1 ​ ​ 7 ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 1 ​ ​ 7 ​ Synthetic leveraged credit fund ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 16 ​ ​ 16 ​ ​ — ​ ​ 16 ​ ​ 16 ​ Total other investments ​ ​ 6 ​ ​ 1 ​ ​ 7 ​ ​ — ​ ​ 16 ​ ​ 16 ​ ​ 6 ​ ​ 17 ​ ​ 23 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total investments $ 1,207 ​ $ 1 ​ $ 1,208 ​ $ 4 ​ $ 238 ​ $ 242 ​ $ 1,211 ​ $ 239 ​ $ 1,450 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ Significant observable inputs ​ Significant other observable inputs ​ Total ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ U.S. ​ U.K. ​ ​ ​ Plans Plan Total Plans Plan Total Plans Plan Total Mutual funds ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. equity funds $ 301 ​ $ — ​ $ 301 ​ $ — ​ $ — ​ $ — ​ $ 301 ​ $ — ​ $ 301 ​ Non-U.S. equity funds ​ ​ 132 ​ ​ — ​ ​ 132 ​ ​ 4 ​ ​ 57 ​ ​ 61 ​ ​ 136 ​ ​ 57 ​ ​ 193 ​ Bond funds ​ ​ 698 ​ ​ — ​ ​ 698 ​ ​ 2 ​ ​ 171 ​ ​ 173 ​ ​ 700 ​ ​ 171 ​ ​ 871 ​ Total mutual funds ​ ​ 1,131 ​ ​ — ​ ​ 1,131 ​ ​ 6 ​ ​ 228 ​ ​ 234 ​ ​ 1,137 ​ ​ 228 ​ ​ 1,365 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and money market funds ​ ​ 6 ​ ​ 4 ​ ​ 10 ​ ​ — ​ ​ — ​ ​ — ​ ​ 6 ​ ​ 4 ​ ​ 10 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total investments $ 1,137 ​ $ 4 ​ $ 1,141 ​ $ 6 ​ $ 228 ​ $ 234 ​ $ 1,143 ​ $ 232 ​ $ 1,375 ​
Schedule of projected benefits payments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. ​ U.K. ​ OPEB ​ ​ ​ ​ Plans Plan Plans Total Years ending December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 $ 84 ​ $ 6 ​ $ 3 ​ $ 93 ​ 2025 ​ ​ 84 ​ ​ 7 ​ ​ 3 ​ ​ 94 ​ 2026 ​ ​ 84 ​ ​ 8 ​ ​ 1 ​ ​ 93 ​ 2027 ​ ​ 85 ​ ​ 8 ​ ​ — ​ ​ 93 ​ 2028 ​ ​ 85 ​ ​ 9 ​ ​ — ​ ​ 94 ​ 2029 - 2033 ​ ​ 427 ​ ​ 58 ​ ​ 1 ​ ​ 486 ​ ​

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Taxes
Components of the provision (benefit) for income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ 2023 2022 2021 Current tax expense (benefit) $ (5) ​ $ 13 ​ $ (7) ​ Deferred tax expense ​ ​ 18 ​ ​ 46 ​ ​ 128 ​ Income tax expense $ 13 ​ $ 59 ​ $ 121 ​
Reconciliation of the differences between income tax expense computed at the Swiss holding company statutory rate and the reported provision for income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ 2023 2022 2021 Income tax benefit at Swiss federal statutory rate $ (74) ​ $ (44) ​ $ (36) ​ Earnings subject to rates different than the Swiss federal statutory rate ​ ​ 129 ​ ​ 52 ​ ​ 78 ​ Deemed profits taxes ​ ​ 11 ​ ​ 10 ​ ​ 17 ​ Withholding taxes ​ ​ 5 ​ ​ 12 ​ ​ 10 ​ Changes in valuation allowance ​ ​ (23) ​ ​ 79 ​ ​ 1,167 ​ Changes in unrecognized tax benefits, net ​ ​ (37) ​ ​ 2 ​ ​ (43) ​ Swiss Federal Act on Tax Reform and AHV Financing ​ ​ — ​ ​ 96 ​ ​ (1,095) ​ Audit settlement ​ ​ — ​ ​ 12 ​ ​ — ​ Changes due to organizational restructuring ​ ​ — ​ ​ (162) ​ ​ 16 ​ Losses on impairment ​ ​ — ​ ​ — ​ ​ 5 ​ Other, net ​ ​ 2 ​ ​ 2 ​ ​ 2 ​ Income tax expense $ 13 ​ $ 59 ​ $ 121 ​
Significant components of deferred tax assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Deferred tax assets ​ ​ ​ ​ ​ ​ ​ Swiss historic depreciation and financing asset costs ​ $ 1,210 ​ $ 1,226 ​ Net operating loss carryforwards ​ 1,264 ​ ​ 1,115 ​ Interest expense limitation ​ ​ 87 ​ ​ 77 ​ United Kingdom charter limitation ​ ​ 53 ​ ​ 53 ​ Accrued expenses ​ ​ 47 ​ ​ 36 ​ Tax credits ​ ​ 4 ​ ​ 11 ​ Deferred income ​ ​ — ​ ​ 7 ​ Accrued payroll costs not currently deductible ​ ​ 16 ​ ​ 18 ​ Loss contingencies ​ ​ 4 ​ ​ 4 ​ Other ​ ​ 54 ​ ​ 43 ​ Valuation allowance ​ ​ (1,884) ​ ​ (1,910) ​ Total deferred tax assets, net of allowance ​ ​ 855 ​ ​ 680 ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ Depreciation ​ ​ (1,342) ​ ​ (1,150) ​ Other ​ ​ (9) ​ ​ (10) ​ Total deferred tax liabilities ​ ​ (1,351) ​ ​ (1,160) ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets (liabilities), net $ (496) ​ $ (480) ​
Reconciliation of unrecognized tax benefits, excluding interest and penalties	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ 2023 ​ 2022 ​ 2021 Balance, beginning of period $ 444 ​ $ 402 ​ $ 378 ​ Additions for current year tax positions ​ ​ 45 ​ ​ 28 ​ ​ 28 ​ Additions for prior year tax positions ​ ​ 5 ​ ​ 62 ​ ​ 46 ​ Reductions related to statute of limitation expirations and changes in law ​ ​ (14) ​ ​ (13) ​ ​ (19) ​ Reductions due to settlements ​ ​ (5) ​ ​ (5) ​ ​ (31) ​ Reductions for prior year tax positions ​ ​ (26) ​ ​ (30) ​ ​ — ​ Balance, end of period $ 449 ​ $ 444 ​ $ 402 ​
Schedule of unrecognized tax benefits, including related interest and penalties	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2023 ​ 2022 Unrecognized tax benefits, excluding interest and penalties ​ $ 449 ​ $ 444 ​ Interest and penalties ​ ​ 9 ​ ​ 27 ​ Unrecognized tax benefits, including interest and penalties ​ $ 458 ​ $ 471 ​

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Loss per share
Schedule of loss per share	The computation of basic and diluted loss per share was as follows (in millions, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Numerator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to controlling interest ​ $ (954) ​ $ (621) ​ $ (592) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares for per share calculation ​ ​ 768 ​ ​ 699 ​ ​ 637 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss per share, basic and diluted ​ $ (1.24) ​ $ (0.89) ​ $ (0.93) ​
Schedule of antidilutive securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Exchangeable bonds ​ ​ 150.8 ​ ​ 128.1 ​ ​ 104.4 ​ Share-based awards ​ ​ 18.6 ​ ​ 15.5 ​ ​ 12.6 ​ Warrants ​ ​ 10.2 ​ ​ — ​ ​ — ​ ​

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies
Schedule of aggregate future payments required under purchase obligations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service ​ ​ ​ Purchase ​ agreement ​ ​ obligations ​ obligations ​ Years ending December 31, ​ ​ ​ ​ ​ ​ ​ 2024 $ 19 ​ $ 131 ​ 2025 ​ ​ 2 ​ ​ 145 ​ 2026 ​ ​ — ​ ​ 149 ​ 2027 ​ ​ — ​ ​ 121 ​ 2028 ​ ​ — ​ ​ 73 ​ Thereafter ​ ​ — ​ ​ 109 ​ Total $ 21 ​ $ 728 ​

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share Based Compensation
Summary of activity for vested and unvested stock options outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average ​ ​ ​ ​ Number ​ Weighted-average ​ remaining ​ Aggregate ​ ​ of shares ​ exercise price ​ contractual term ​ intrinsic value ​ under option per share (years) (in millions) Outstanding at January 1, 2023 ​ 4,175,520 ​ $ 10.63 ​ 4.82 ​ $ — ​ Forfeited ​ (25,017) ​ ​ 59.30 ​ ​ ​ ​ ​ ​ Expired ​ (66,574) ​ ​ 59.30 ​ ​ ​ ​ ​ ​ Outstanding at December 31, 2023 ​ 4,083,929 ​ $ 9.54 ​ 3.92 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Vested and exercisable at December 31, 2023 ​ 4,083,929 ​ $ 9.54 ​ 3.92 ​ $ — ​
Service awards
Share Based Compensation
Summary of unvested deferred units activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ Weighted-average ​ ​ ​ ​ ​ ​ ​ of ​ grant-date fair value ​ ​ ​ ​ ​ ​ units per unit Unvested at January 1, 2023 ​ ​ ​ ​ ​ ​ 12,047,500 ​ $ 3.25 Granted ​ ​ ​ ​ ​ ​ 3,744,049 ​ ​ 7.23 ​ Vested ​ ​ ​ ​ ​ ​ (6,200,155) ​ ​ 2.94 ​ Forfeited ​ ​ ​ ​ ​ ​ (31,386) ​ ​ 3.56 ​ Unvested at December 31, 2023 ​ ​ ​ ​ ​ ​ 9,560,008 ​ $ 5.01 ​
Performance awards
Share Based Compensation
Summary of unvested deferred units activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ Weighted-average ​ ​ ​ ​ ​ ​ ​ of ​ grant-date fair value ​ ​ ​ ​ ​ ​ units per unit Unvested at January 1, 2023 ​ ​ ​ ​ ​ ​ 6,545,369 ​ $ 3.81 ​ Granted ​ ​ ​ ​ ​ ​ 1,912,292 ​ ​ 6.74 ​ Vested ​ ​ ​ ​ ​ ​ (3,025,512) ​ ​ 3.70 ​ Unvested at December 31, 2023 ​ ​ ​ ​ ​ ​ 5,432,149 ​ $ 4.91 ​

Supplemental Balance Sheet In_2

Supplemental Balance Sheet Information (Tables)	12 Months Ended
	Dec. 31, 2023
Supplemental Balance Sheet Information
Schedule of other current liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Other current liabilities ​ ​ ​ ​ ​ ​ ​ Accrued employee benefits and payroll-related liabilities $ 145 ​ $ 156 ​ Accrued interest ​ ​ 146 ​ ​ 113 ​ Accrued taxes, other than income ​ ​ 47 ​ ​ 41 ​ Finance lease liability ​ ​ 43 ​ ​ 40 ​ Operating lease liabilities ​ ​ 12 ​ ​ 7 ​ Deferred revenues ​ ​ 165 ​ ​ 124 ​ Contingent liabilities ​ ​ 116 ​ ​ 58 ​ Other ​ ​ 7 ​ ​ — ​ Total other current liabilities $ 681 ​ $ 539 ​
Schedule of other long term liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 Other long-term liabilities ​ ​ ​ ​ ​ ​ ​ Postemployment benefit plan obligations $ 121 ​ $ 170 ​ Finance lease liability ​ ​ 276 ​ ​ 323 ​ Operating lease liabilities ​ ​ 108 ​ ​ 100 ​ Income taxes payable ​ ​ 80 ​ ​ 129 ​ Deferred revenues ​ ​ 233 ​ ​ 204 ​ Other ​ ​ 40 ​ ​ 39 ​ Total other long-term liabilities $ 858 ​ $ 965 ​ ​

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2023
Supplemental Cash Flow Information
Schedule of changes in other operating assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 2022 2021 Changes in other operating assets and liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Increase) decrease in accounts receivable ​ ​ $ (99) ​ $ (15) ​ $ 137 ​ Increase in other assets ​ ​ ​ ​ (98) ​ ​ (12) ​ ​ (13) ​ Increase (decrease) in accounts payable and other current liabilities ​ ​ ​ ​ 135 ​ ​ 8 ​ ​ (52) ​ Decrease in other long-term liabilities ​ ​ ​ ​ (7) ​ ​ (2) ​ ​ (3) ​ Change in income taxes receivable / payable, net ​ ​ ​ ​ (36) ​ ​ (42) ​ ​ (17) ​ Change in receivables from / payables to affiliates, net ​ ​ ​ ​ (8) ​ ​ (12) ​ ​ (15) ​ ​ ​ ​ $ (113) ​ $ (75) ​ $ 37 ​
Additional cash flow information	Additional cash flow information was as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years ended December 31, ​ ​ ​ 2023 2022 2021 Certain cash operating activities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash payments for interest ​ ​ $ 408 ​ $ 355 ​ $ 429 ​ Cash payments for income taxes ​ ​ ​ ​ 41 ​ ​ 66 ​ ​ 57 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-cash investing and financing activities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital additions accrued at end of period ​ (a) ​ $ 36 ​ $ 31 ​ $ 28 ​ Capital additions acquired in exchange for debt ​ (b) ​ ​ — ​ ​ 382 ​ ​ — ​ Acquisition of outstanding ownership interests in exchange for shares ​ (c) ​ ​ 99 ​ ​ — ​ ​ — ​ Debt investment exchanged for equity ownership interests ​ (d) ​ ​ 37 ​ ​ — ​ ​ — ​ Finance lease installments settled with credits issued to customer ​ (e) ​ ​ 44 ​ ​ 41 ​ ​ — ​ Shares issued in exchanges of exchangeable bonds ​ (f) ​ ​ 434 ​ ​ — ​ ​ — ​ Debt and warrants issued in exchange transactions ​ (g) ​ ​ — ​ ​ 110 ​ ​ 260 ​ (a) Additions to property and equipment for which we had accrued a corresponding liability in accounts payable at the end of the period. See Note 7—Long-Lived Assets . (b) In the year ended December 31, 2022, we borrowed an aggregate principal amount of $439 million under the Shipyard Loans to satisfy a portion of the final milestone payments due upon delivery of Deepwater Atlas and Deepwater Titan and recorded the initial carrying amount, net of imputed interest, with a corresponding entry to construction in progress, recorded in property and equipment. See Note 7—Long-Lived Assets and Note 9—Debt . (c) In September 2023, we issued 11.9 million Transocean Ltd. shares to acquire the outstanding ownership interests in Liquila. See Note 4—Unconsolidated Affiliates , Note 7—Long-Lived Assets and Note 14—Equity . (d) In September 2023, we agreed to exchange borrowings due to us under a financing arrangement with Orion for additional equity ownership interests in Orion. See Note 4—Unconsolidated Affiliates . (e) In the years ended December 31, 2023 and 2022, we agreed to settle installments due to the lessor under our finance lease by issuing corresponding credits to our customer for amounts due to us under the drilling contract. See Note 8—Leases . (f) In the year ended December 31, 2023, we issued 65.1 million Transocean Ltd. shares to certain holders that elected to exchange the 2.50% Senior Guaranteed Exchangeable Bonds, the 4.00% Senior Guaranteed Exchangeable Bonds and the 4.625% Senior Guaranteed Exchangeable Bonds. See Note 9—Debt and Note 14—Equity . (g) In the year ended December 31, 2022, in connection with the 2022 Private Exchange, we issued $112 million aggregate principal amount of the 4.625% Senior Guaranteed Exchangeable Bonds with an estimated fair value of $105 million and 6.7 million warrants to purchase Transocean Ltd. shares with an estimated fair value of $5 million. In the year ended December 31, 2021, in connection with the 2021 Private Exchange, we issued $294 million aggregate principal amount of the 4.00% Senior Guaranteed Exchangeable Bonds with an estimated fair value of $260 million. See Note 9—Debt and Note 14—Equity .

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2023
Financial Instruments
Carrying amounts and fair values of the financial instruments	The carrying amounts and fair values of our financial instruments were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ Carrying ​ Fair ​ Carrying ​ Fair ​ amount value amount value Cash and cash equivalents $ 762 ​ $ 762 ​ $ 683 ​ $ 683 ​ Restricted cash and cash equivalents ​ ​ 233 ​ ​ 233 ​ ​ 308 ​ ​ 308 ​ Long-term loans receivable from unconsolidated affiliates ​ ​ 6 ​ ​ 6 ​ ​ 41 ​ ​ 43 ​ Total debt ​ ​ 7,413 ​ ​ 7,308 ​ ​ 7,347 ​ ​ 6,412 ​

Business (Details)

Business (Details)	12 Months Ended
	Dec. 31, 2023 item segment
Number of mobile offshore drilling units	37
Number of operating segments | segment	1
Ultra-deepwater floaters
Number of mobile offshore drilling units	28
Number of mobile offshore drilling units under construction	1
Harsh environment floaters
Number of mobile offshore drilling units	9

Significant Accounting Polici_3

Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Functional currency
Net foreign currency exchange gain (loss)	$ 10	$ (8)	$ (1)
Materials and supplies
Materials and supplies, allowance for obsolescence	$ 198	$ 199
Property and equipment
Property and equipment as a percentage of total assets	84%
Equity method investments and impairment
Loss on impairment of investment in unconsolidated affiliates	$ 5		$ 37
Drilling rig units
Property and equipment
Estimated original useful life	35 years
Buildings and improvements | Minimum
Property and equipment
Estimated original useful life	3 years
Buildings and improvements | Maximum
Property and equipment
Estimated original useful life	30 years
Machinery and equipment | Minimum
Property and equipment
Estimated original useful life	4 years
Machinery and equipment | Maximum
Property and equipment
Estimated original useful life	20 years

Significant Accounting Polici_4

Significant Accounting Policies (Pensions) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pension and other postretirement benefits
Recognition period of investment gains or losses related to asset valuation for determining net periodic benefit cost	5 years
Conditional amortization gains or losses as percentage of greater of plan assets or liabilities, minimum	10%
Pension liability, current and noncurrent	$ 125	$ 174
Pension asset, non-current	$ 31	$ 44

Unconsolidated Affiliates (Deta

Unconsolidated Affiliates (Details) shares in Millions, $ in Millions		1 Months Ended				12 Months Ended
	Sep. 15, 2023 USD ($) shares	Sep. 30, 2023 USD ($) shares	Feb. 28, 2023 USD ($)	Nov. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Investments
Equity in losses						$ (14)	$ (24)	$ (10)
Aggregate carrying amount of equity investment						216	113
Investment in unconsolidated affiliate						10	42	1
Related party accounts payable						323	281
Cash investments in loans to unconsolidated affiliates						3	5	33
Loss on impairment of investment in unconsolidated affiliates						5		$ 37
Equity Method Investee
Investments
Related party receivable						14	32
Related party accounts payable						$ 4	2
Liquila
Investments
Total contractual obligation				$ 200
Discount rate
Investments
Investment fair value measurement								0.12
Global Sea Mineral Resources
Investments
Equity ownership (as a percent)						16%
Investment in unconsolidated affiliate			$ 10
Equity investment non-cash contribution			$ 85
Orion/Transocean Norge
Investments
Equity ownership (as a percent)						33%
Non-cash net settlement of accounts receivable and payable						$ 25
Cash investments in loans to unconsolidated affiliates					$ 33
Long-term loans receivable from unconsolidated affiliates						6	41
Orion/Transocean Norge | Equity Method Investee
Investments
Aggregate carrying amount of equity investment							37
Orion/Transocean Norge | London Interbank Offered Rate [Member]
Investments
Loan receivable interest rate (as a percent)					6.50%
Orion/Transocean Norge | Orion/Transocean Norge
Investments
Loan payable					$ 100
Orion/Transocean Norge | Reimbursements, Agent Fees and Other Receipts
Investments
Related party transaction						55	54	$ 24
Orion/Transocean Norge | Services and Equipment
Investments
Related party transaction						49	40	16
Orion/Transocean Norge | Rent Expense
Investments
Related party transaction						26	11	12
Orion/Transocean Norge | Charter rig and other equipment
Investments
Related party transaction						$ 27	10	15
Ocean Minerals
Investments
Equity ownership (as a percent)						19%
Nauticus Robotics
Investments
Equity ownership (as a percent)						22%
Liquila
Investments
Aggregate carrying amount of equity investment							15
Investment in unconsolidated affiliate				15
Liquila | Perestroika AS
Investments
Investment in unconsolidated affiliate				$ 10
Liquila | Third Party
Investments
Equity ownership (as a percent)				67%
Liquila | Transocean Inc | Perestroika AS
Investments
Equity ownership (as a percent)				11%
Other Investments
Investments
Related party transaction						$ 12	$ 7	$ 6
Liquila
Investments
Newly issued shares in asset acquisition (in shares) | shares	11.9	11.9
Value shares issued in asset acquisition	$ 99	$ 99				$ 99
Related party accounts payable		$ 19
Liquila | Perestroika AS
Investments
Newly issued shares in asset acquisition (in shares) | shares	2
Value shares issued in asset acquisition	$ 16.4

Revenues (Disaggregation) (Deta

Revenues (Disaggregation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue
Contract drilling revenues	$ 2,832	$ 2,575	$ 2,556
U.S.
Revenue
Contract drilling revenues	1,433	1,135	1,098
Norway
Revenue
Contract drilling revenues	603	835	790
Brazil
Revenue
Contract drilling revenues	298	240	237
Other Countries
Revenue
Contract drilling revenues	498	365	431
Ultra-deepwater floaters
Revenue
Contract drilling revenues	2,072	1,708	1,720
Ultra-deepwater floaters | U.S.
Revenue
Contract drilling revenues	1,433	1,135	1,096
Ultra-deepwater floaters | Brazil
Revenue
Contract drilling revenues	298	240	237
Ultra-deepwater floaters | Other Countries
Revenue
Contract drilling revenues	341	333	387
Harsh environment floaters
Revenue
Contract drilling revenues	760	867	836
Harsh environment floaters | U.S.
Revenue
Contract drilling revenues			2
Harsh environment floaters | Norway
Revenue
Contract drilling revenues	603	835	790
Harsh environment floaters | Other Countries
Revenue
Contract drilling revenues	$ 157	$ 32	$ 44

Revenues (Customers) (Details)

Revenues (Customers) (Details) - Revenue - Customer	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Shell
Concentration Risk
Percentage of concentration	27%	33%	31%
Equinor
Concentration Risk
Percentage of concentration	16%	25%	30%
TotalEnergies
Concentration Risk
Percentage of concentration	12%
Petrobras
Concentration Risk
Percentage of concentration	11%	11%

Revenues (Contract liabilities)

Revenues (Contract liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Contract balances
Deferred contract revenues, recorded in other current liabilities	$ 165	$ 124
Deferred contract revenues, recorded in other long-term liabilities	233	204
Total contract liabilities	$ 398	$ 328	$ 348

Revenues (Changes) (Details)

Revenues (Changes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Changes to contract liabilities
Total contract liabilities, at beginning of period	$ 328	$ 348
Decrease due to recognition of revenues for goods and services	(189)	(119)
Increase due to goods and services transferred over time	259	99
Total contract liabilities, at end of period	$ 398	$ 328

Revenues (Pre-operating) (Detai

Revenues (Pre-operating) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues
Recognized pre-operating costs	$ 69	$ 47	$ 48
Unrecognized pre-operating costs	$ 221	$ 26

Contract Intangible Assets (Rol

Contract Intangible Assets (Roll forward) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Gross carrying amount
Beginning Balance, Gross	$ 907	$ 907
Amortization	(52)	(117)	$ (220)
Ending Balance, Gross	907	907	907
Accumulated amortization
Beginning Balance, amortization	(851)	(734)
Amortization	(52)	(117)	(220)
Ending Balance, amortization	(903)	(851)	(734)
Net carrying amount
Beginning Balance, Net	56	173
Amortization	(52)	(117)	(220)
Ending Balance, Net	$ 4	$ 56	$ 173

Contract Intangible Assets (Amo

Contract Intangible Assets (Amortization) (Details) $ in Millions	Dec. 31, 2023 USD ($)
Contract Intangible Assets
2024	$ 4

Long-Lived Assets - Disaggregat

Long-Lived Assets - Disaggregation (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 17,427	$ 17,962
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	7,472	6,514
Greece
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	2,652	3,022
Norway
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	2,103	3,255
Other countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 5,200	$ 5,171

Long-Lived Assets - Constructio

Long-Lived Assets - Construction work in progress (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Changes in construction work in progress
Total capital expenditures	$ 427	$ 717	$ 208
Non-cash capital additions acquired in exchange for issuance of shares	126
Non-cash capital additions financed under Shipyard Loan		382
Changes in accrued capital additions	5	3	13
Capitalized interest costs on construction work in progress	39	73	50
Construction in Progress
Changes in construction work in progress
Construction work in progress, at beginning of period	1,195	1,017	828
Construction work in progress, at end of period	522	1,195	1,017
New builds
Changes in construction work in progress
Total capital expenditures	331	669	174
Property and equipment placed into service	(1,157)	(882)
Other property and equipment
Changes in construction work in progress
Total capital expenditures	96	48	34
Property and equipment placed into service	$ (74)	$ (42)	$ (32)

Long-Lived Assets (Acquisition

Long-Lived Assets (Acquisition and Disposal) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2023	Jun. 30, 2023
Acquisition and Disposals
Cash and cash equivalents	$ 762	$ 683
Accounts payable	323	281
Gain (loss) on the sale of assets	(183)	(10)	$ (62)
Proceeds from disposal of assets, net	10	7	9
Assets sold, not discontinued operations | Rig sales
Acquisition and Disposals
Gain (loss) on the sale of assets	$ (169)		$ (57)
Gain (loss) on the sale of assets per diluted share	$ (0.22)		$ (0.09)
Gain (loss) on disposal of assets, tax effect	$ 0		$ 0
Proceeds from disposal of assets, net			4
Assets sold, not discontinued operations | Other property and equipment
Acquisition and Disposals
Gain (loss) on the sale of assets	(14)	(10)	(5)
Proceeds from disposal of assets, net	4	$ 7	$ 5
Assets held for sale
Acquisition and Disposals
Assets held for sale	$ 49				$ 49
Liquila
Acquisition and Disposals
Construction work in progress				$ 126
Cash and cash equivalents				7
Accounts payable				$ 19

Long-Lived Assets (Impairment h

Long-Lived Assets (Impairment held for sale) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares
Long-Lived Assets
Aggregate loss on impairment of assets held for sale	$ 57
Loss associated with impairment, net of tax (per share) | $ / shares	$ 0.07
Aggregate loss on impairment of assets held for sale, tax effect	$ 0

Leases (Operating leases) (Deta

Leases (Operating leases) (Details)	Dec. 31, 2023
Leases
Weighted average discount rate, operating leases (as a percent)	6.70%
Weighted-average remaining lease term, operating leases	10 years 8 months 12 days

Leases (Finance lease) (Details

Leases (Finance lease) (Details)	12 Months Ended
	Dec. 31, 2023 USD ($)
Leases
Implicit interest rate (as a percent)	7.80%
End of lease obligation	$ 1

Leases (Lease costs) (Details)

Leases (Lease costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases
Short-term lease costs	$ 4	$ 14	$ 17
Operating lease costs	14	12	12
Finance lease costs, amortization of right-of-use asset	20	20	20
Finance lease costs, interest on lease liability	27	30	33
Total lease costs	$ 65	$ 76	$ 82

Leases - (Cash flow) (Details)

Leases - (Cash flow) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases
Operating cash flows from operating leases	$ 17	$ 14	$ 13
Operating cash flows from finance lease		8	37
Financing cash flows from finance lease		$ 3	$ 33

Leases (Maturity) (Details)

Leases (Maturity) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Operating lease maturity
2024	$ 19
2025	19
2026	18
2027	15
2028	13
Thereafter	89
Total future minimum rental payment	173
Less amount representing imputed interest	(53)
Present value of future minimum rental payments under operating leases	120
Current portion, recorded in other current liabilities	12	$ 7
Long-term lease liabilities, recorded in other long-term liabilities	108	100
Finance lease maturity
2024	65
2025	70
2026	71
2027	70
2028	71
Thereafter	47
Total future minimum rental payment	394
Less amount representing imputed interest	(75)
Present value of future minimum rental payments under finance leases	319
Current portion, recorded in other current liabilities	43	40
Long-term lease liabilities, recorded in other long-term liabilities	$ 276	$ 323

Debt (Details)

Debt (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Principal amount
Total installments	$ 7,413	$ 7,347
Debt due within one year	320	652
Long-term debt	6,712	6,311
Carrying amount
Debt due within one year	370	719
Long-term debt	$ 7,043	6,628
0.50% Exchangeable Senior Bonds due January 2023
Principal amount
Total installments		49
Debt due within one year		49
Carrying amount
Total debt		49
Debt due within one year		49
Debt instrument interest rate stated percentage	0.50%
5.375% Senior Secured Notes due May 2023
Principal amount
Total installments		243
Debt due within one year		243
Carrying amount
Total debt		242
Debt due within one year		242
Debt instrument interest rate stated percentage	5.375%
5.875% Senior Secured Notes due January 2024
Principal amount
Total installments		352
Debt due within one year		83
Carrying amount
Total debt		350
Debt due within one year		81
Debt instrument interest rate stated percentage	5.875%
7.75% Senior Secured Notes due October 2024
Principal amount
Total installments		240
Debt due within one year		60
Carrying amount
Total debt		238
Debt due within one year		59
Debt instrument interest rate stated percentage	7.75%
6.25% Senior Secured Notes due December 2024
Principal amount
Total installments		250
Debt due within one year		62
Carrying amount
Total debt		248
Debt due within one year		61
Debt instrument interest rate stated percentage	6.25%
6.125% Senior Secured Notes due August 2025
Principal amount
Total installments		336
Debt due within one year		66
Carrying amount
Total debt		332
Debt due within one year		64
Debt instrument interest rate stated percentage	6.125%
7.25% Senior Notes due November 2025
Principal amount
Total installments	$ 354	354
Carrying amount
Total debt	$ 352	351
Debt instrument interest rate stated percentage	7.25%
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Principal amount
Total installments	$ 234	294
Carrying amount
Total debt	$ 221	271
Debt instrument interest rate stated percentage	4%
7.50% Senior Notes due January 2026
Principal amount
Total installments	$ 569	569
Carrying amount
Total debt	$ 567	566
Debt instrument interest rate stated percentage	7.50%
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Principal amount
Total installments		238
Carrying amount
Total debt		265
Debt due within one year		6
Debt instrument interest rate stated percentage	2.50%
11.50% Senior Guaranteed Notes due January 2027
Principal amount
Total installments	$ 687	687
Carrying amount
Total debt	938	1,008
Debt due within one year	$ 71	70
Debt instrument interest rate stated percentage	11.50%
6.875% Senior Secured Notes due February 2027
Principal amount
Total installments	$ 413	482
Debt due within one year	83	69
Carrying amount
Total debt	409	477
Debt due within one year	$ 81	67
Debt instrument interest rate stated percentage	6.875%
8.00% Senior Notes due February 2027
Principal amount
Total installments	$ 612	612
Carrying amount
Total debt	$ 609	608
Debt instrument interest rate stated percentage	8%
7.45% Notes due April 2027
Principal amount
Total installments	$ 52	52
Carrying amount
Total debt	$ 52	52
Debt instrument interest rate stated percentage	7.45%
8.00% Debentures due April 2027
Principal amount
Total installments	$ 22	22
Carrying amount
Total debt	$ 22	22
Debt instrument interest rate stated percentage	8%
4.50% Shipyard Loans due September 2027
Principal amount
Total installments	$ 420	439
Debt due within one year	90	20
Carrying amount
Total debt	384	389
Debt due within one year	$ 75	20
Debt instrument interest rate stated percentage	4.50%
8.375% Senior Secured Notes due February 2028
Principal amount
Total installments	$ 525
Carrying amount
Total debt	$ 518
Debt instrument interest rate stated percentage	8.375%
7.00% Notes due June 2028
Principal amount
Total installments	$ 261	261
Carrying amount
Total debt	$ 264	264
Debt instrument interest rate stated percentage	7%
8.00% Senior Secured Notes due September 2028
Principal amount
Total installments	$ 325
Debt due within one year	30
Carrying amount
Total debt	321
Debt due within one year	$ 30
Debt instrument interest rate stated percentage	8%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Principal amount
Total installments	$ 259	300
Carrying amount
Total debt	$ 486	440
Debt instrument interest rate stated percentage	4.625%
8.75% Senior Secured Notes Due February 2030
Principal amount
Total installments	$ 1,116
Debt due within one year	117
Carrying amount
Total debt	1,094
Debt due within one year	$ 113
Debt instrument interest rate stated percentage	8.75%
7.50% Notes due April 2031
Principal amount
Total installments	$ 396	396
Carrying amount
Total debt	$ 395	394
Debt instrument interest rate stated percentage	7.50%
6.80% Senior Notes due March 2038
Principal amount
Total installments	$ 610	610
Carrying amount
Total debt	$ 605	605
Debt instrument interest rate stated percentage	6.80%
7.35% Senior Notes due December 2041
Principal amount
Total installments	$ 177	177
Carrying amount
Total debt	$ 176	176
Debt instrument interest rate stated percentage	7.35%
3.80% Senior Notes due October 2022
Carrying amount
Debt instrument interest rate stated percentage	3.80%
Principal installments
Principal amount
Total installments	$ 7,032	$ 6,963

Debt (Maturities) (Details)

Debt (Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Scheduled maturities of debt
Total installments	$ 7,413	$ 7,347
Total Installments
Scheduled maturities of debt
2024	391
2025	1,140
2026	1,182
2027	1,936
2028	664
Thereafter	1,970
Total installments	7,283
Total unamortized debt-related balances, net	(220)
Bifurcated compound exchange feature, at estimated fair value	350
Total carrying amount of debt	7,413
Principal installments
Scheduled maturities of debt
2024	320
2025	1,068
2026	1,110
2027	1,900
2028	664
Thereafter	1,970
Total installments	7,032	$ 6,963
Other installments
Scheduled maturities of debt
2024	71
2025	72
2026	72
2027	36
Total installments	$ 251

Debt (Credit Agreements) (Detai

Debt (Credit Agreements) (Details) $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 30, 2022 USD ($)
Debt
Aggregate principal amount outstanding	$ 7,347		$ 7,413	$ 7,347
Aggregate cash payment to acquire property			427	717	$ 208
Five-Year Revolving Credit Facility
Debt
Early maturity trigger, principal due within 91 days			200
Early maturity trigger available cash			250
Permitted commitment increase			$ 250
Minimum guarantee coverage ratio			3
Minimum collateral coverage ratio.			2.1
Debt to capitalization ratio			0.60
Minimum liquidity			$ 500
Aggregate carrying amount assets pledged			4,710
Cross default trigger under credit facility			$ 125
Commitment fee percentage at period end			0.625%
Credit facility amount outstanding			$ 0
Letters of credit issued and outstanding			13
Credit facility available borrowing capacity			587,000
Five-Year Revolving Credit Facility | June 2023
Debt
Borrowing capacity, maximum			$ 600
Five-Year Revolving Credit Facility | Adjusted LIBOR
Debt
Spread on variable rate basis (as a percent)			2.875%
Five-Year Revolving Credit Facility | Term SOFR
Debt
Spread on variable rate basis (as a percent)			0.10%
4.50% Shipyard Loan due June 2027
Debt
Aggregate principal amount outstanding	439		$ 420	439
Debt instrument face value	439	$ 349		439		$ 90
Aggregate cash payment to acquire property	325	46
Non-cash capital addition	$ 82	$ 300		$ 382
Debt instrument interest rate stated percentage			4.50%
4.50% Shipyard Loan due June 2027 | Discount rate
Debt
Debt fair value measurement input	0.076	0.094		0.076
7.35% Senior Notes due December 2041
Debt
Aggregate principal amount outstanding	$ 177		$ 177	$ 177
Debt instrument interest rate stated percentage			7.35%
Interest rate, as adjusted (as a percent)			9.35%

Debt (Interest Expense) (Detail

Debt (Interest Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest Expense
Amortization	$ 51	$ 33	$ 25
Bifurcated compound exchange feature	127	157
Total interest expense	646	561	447
Exchangeable bonds
Interest Expense
Contractual interest	24	16	11
Amortization	19	9	5
Bifurcated compound exchange feature	127	157
Total interest expense	$ 170	$ 182	$ 16

Debt (Exchange and Issue) (Deta

Debt (Exchange and Issue) (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended					12 Months Ended
	Oct. 31, 2023 USD ($) shares	Jul. 31, 2023 USD ($) shares	Apr. 30, 2023 USD ($) shares	Sep. 30, 2022 USD ($) $ / shares shares	Feb. 28, 2021 USD ($) $ / shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($)
Debt
Restricted cash and cash equivalents						$ 233	$ 308
Shares issuable (in shares)						434
Aggregate principal amount of debt issued in exchanges							112	$ 294
Shares issued upon conversion (in shares) | shares	26.5					65.1
Aggregate principal amount to redeem							193	402
Fair value adjustment to bifurcated compound exchange feature						$ 127	157
Interest expense						646	561	447
Number of warrants issued to subscribe | shares				22.2
Aggregate cash payment							75	90
Proceeds from issuance of debt						$ 1,983	$ 175
Shares issued in exchange (in shares) | shares	3.1
2022 Private Exchange
Debt
Number of warrants issued to subscribe | shares				6.7			6.7
Gains (losses) on restructuring				$ 6
Gains (losses) on restructuring (in dollars per share) | $ / shares				$ 0.01
Exchanged
Debt
Aggregate principal amount of debt issued in exchanges							$ 112	294
Aggregate principal amount to redeem							116	323
Aggregate cash payment								11
0.50% Exchangeable Senior Bonds due January 2023
Debt
Debt instrument interest rate stated percentage						0.50%
Aggregate principal amount to redeem							91	323
Aggregate cash payment					$ 11
Original debt in exchange					323
Gains (losses) on restructuring					$ 51
Gains (losses) on restructuring (in dollars per share) | $ / shares					$ 0.08
0.50% Exchangeable Senior Bonds due January 2023 | 2022 Private Exchange
Debt
Original debt in exchange				$ 73
0.50% Exchangeable Senior Bonds due January 2023 | Exchanged
Debt
Aggregate principal amount to redeem							73	323
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Debt
Debt instrument interest rate stated percentage						2.50%
Debt conversion ratio		0.1621626	0.1621626
Shares issued upon conversion (in shares) | shares		4	34.6
Aggregate principal amount to redeem		$ 25
2.50% Senior Guaranteed Exchangeable Bonds due January 2027 | Perestroika AS
Debt
Aggregate principal amount of debt issued in exchanges			$ 213
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Debt
Debt instrument interest rate stated percentage						4%
Debt conversion ratio	0.1904762					0.1904762
Debt conversion (in dollars per share) | $ / shares						$ 5.25
Effective interest rate (as a percent)						6.90%
Fair value of debt						$ 341
Aggregate principal amount of debt issued in exchanges					$ 294			$ 294
Aggregate principal amount to redeem	$ 60
Original debt in exchange					$ 260
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Debt
Debt instrument interest rate stated percentage						4.625%
Debt conversion ratio	0.2906618					0.2906618
Debt conversion (in dollars per share) | $ / shares						$ 3.44
Effective interest rate (as a percent)						18.30%
Fair value of debt						$ 567
Aggregate principal amount of debt issued in exchanges							112
Aggregate principal amount to redeem	$ 41					41
Debt instrument face value				$ 188
Bifurcated compound exchange feature, at estimated fair value						$ 350	295
Amount to repurchase upon the occurrence of certain events (as a percent)				1.15
Trading days for calculation of average stock price				20 days
Number of warrants issued to subscribe | shares				15.5
Original debt in exchange				$ 281
Proceeds from issuance of debt				188
4.625% Senior Guaranteed Exchangeable Bonds due September 2029 | 2022 Private Exchange
Debt
Aggregate principal amount of debt issued in exchanges				73
Debt instrument face value				300
11.50% Senior Guaranteed Notes due January 2027
Debt
Debt instrument interest rate stated percentage						11.50%
8.00% Senior Notes due February 2027
Debt
Debt instrument interest rate stated percentage						8%
7.25% Senior Notes due November 2025
Debt
Debt instrument interest rate stated percentage						7.25%
Aggregate principal amount to redeem							57
7.25% Senior Notes due November 2025 | 2022 Private Exchange
Debt
Aggregate principal amount of debt issued in exchanges				39
Original debt in exchange				$ 43
7.25% Senior Notes due November 2025 | Exchanged
Debt
Aggregate principal amount to redeem							$ 43
Senior Secured Notes
Debt
Restricted cash and cash equivalents						$ 198
Redemption price of debt instrument (as a percent)						100%
Aggregate carrying amount assets pledged						$ 6,130

Debt (Debt issuance) (Details)

Debt (Debt issuance) (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Oct. 31, 2023	Jan. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Debt
Proceeds from issuance of debt			$ 1,983	$ 175
8.375% Senior Secured Notes due February 2028
Debt
Debt instrument face value		$ 525
Debt instrument interest rate stated percentage			8.375%
Proceeds from issuance of debt		$ 516
Redemption price of debt instrument (as a percent)		100%
8.75% Senior Secured Notes Due February 2030
Debt
Debt instrument face value		$ 1,175
Debt instrument interest rate stated percentage			8.75%
Proceeds from issuance of debt		$ 1,148
Redemption price of debt instrument (as a percent)		100%
8.00% Senior Secured Notes due September 2028
Debt
Debt instrument face value	$ 325
Debt instrument interest rate stated percentage	8%
Proceeds from issuance of debt	$ 319
Redemption price of debt instrument (as a percent)	100%

Debt (Settled) (Details)

Debt (Settled) (Details) - USD ($) $ in Millions			1 Months Ended		12 Months Ended
	Jan. 30, 2023	Dec. 15, 2021	Oct. 31, 2023	Feb. 28, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt
Aggregate principal amount of debt retired						$ 193	$ 402
Aggregate cash payment						75	90
Aggregate principal amount of debt issued in exchanges						112	294
Aggregate fair value of warrants issued in exchanges						5
Aggregate net gain (loss)					$ (31)	8	51
Repayments of debt					$ 1,717	554	606
6.375% Senior Notes due December 2021
Debt
Repayments of debt		$ 38
5.52% Senior Secured Notes due May 2022
Debt
Aggregate principal amount of debt retired						18
Debt instrument interest rate stated percentage					5.52%
0.50% Exchangeable Senior Bonds due January 2023
Debt
Aggregate principal amount of debt retired						91	323
Aggregate cash payment				$ 11
Repayments of debt	$ 49
Debt instrument interest rate stated percentage					0.50%
5.375% Senior Secured Notes due May 2023
Debt
Aggregate principal amount of debt retired							11
Debt instrument interest rate stated percentage					5.375%
5.875% Senior Secured Notes due January 2024
Debt
Aggregate principal amount of debt retired							68
Debt instrument interest rate stated percentage					5.875%
7.75% Senior Secured Notes due October 2024
Debt
Debt instrument interest rate stated percentage					7.75%
6.25% Senior Secured Notes due December 2024
Debt
Debt instrument interest rate stated percentage					6.25%
6.125% Senior Secured Notes due August 2025
Debt
Debt instrument interest rate stated percentage					6.125%
7.25% Senior Notes due November 2025
Debt
Aggregate principal amount of debt retired						57
Debt instrument interest rate stated percentage					7.25%
3.80% Senior Notes due October 2022
Debt
Aggregate principal amount of debt retired						27
Debt instrument interest rate stated percentage					3.80%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Debt
Aggregate principal amount of debt retired			$ 41		$ 41
Aggregate principal amount of debt issued in exchanges						112
Aggregate net gain (loss)					$ 1
Debt instrument interest rate stated percentage					4.625%
Aggregate of unspecified debt
Debt
Repayments of debt					$ 262	479	478
Redeemed
Debt
Aggregate principal amount of debt retired					1,380	77	79
Aggregate cash payment					1,402	75	79
Aggregate net gain (loss)					(32)	2
Redeemed | 5.52% Senior Secured Notes due May 2022
Debt
Aggregate principal amount of debt retired						18
Redeemed | 0.50% Exchangeable Senior Bonds due January 2023
Debt
Aggregate principal amount of debt retired						18
Redeemed | 5.375% Senior Secured Notes due May 2023
Debt
Aggregate principal amount of debt retired					243		11
Redeemed | 5.875% Senior Secured Notes due January 2024
Debt
Aggregate principal amount of debt retired					311		68
Redeemed | 7.75% Senior Secured Notes due October 2024
Debt
Aggregate principal amount of debt retired					240
Redeemed | 6.25% Senior Secured Notes due December 2024
Debt
Aggregate principal amount of debt retired					250
Redeemed | 6.125% Senior Secured Notes due August 2025
Debt
Aggregate principal amount of debt retired					$ 336
Redeemed | 7.25% Senior Notes due November 2025
Debt
Aggregate principal amount of debt retired						14
Redeemed | 3.80% Senior Notes due October 2022
Debt
Aggregate principal amount of debt retired						27
Exchanged
Debt
Aggregate principal amount of debt retired						116	323
Aggregate cash payment							11
Aggregate principal amount of debt issued in exchanges						112	294
Aggregate fair value of warrants issued in exchanges						5
Aggregate net gain (loss)						6	51
Exchanged | 0.50% Exchangeable Senior Bonds due January 2023
Debt
Aggregate principal amount of debt retired						73	$ 323
Exchanged | 7.25% Senior Notes due November 2025
Debt
Aggregate principal amount of debt retired						$ 43

Postemployment Benefit Plans (D

Postemployment Benefit Plans (DefCont) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Postemployment Benefit Plans
Contribution expense	$ 58	$ 61	$ 52

Postemployment Benefit Plans (C

Postemployment Benefit Plans (Costs) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) plan	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Net periodic benefit costs, before tax
Interest cost	$ 74	$ 56	$ 53
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Expected return on plan assets	$ (95)	$ (72)	(79)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Settlements and curtailments			(2)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement and Curtailment Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Actuarial loss, net	$ 2	$ 5	12
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Prior service gain, net	$ (2)	$ (2)	(2)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Net periodic benefit costs (income)	$ (21)	$ (13)	$ (18)
U.S.
Weighted-average assumptions
Discount rate (as a percent)	5.06%	2.92%	2.60%
Expected rate of return (as a percent)	6.41%	4.81%	5.51%
U.S. | Funded Plan
Postemployment Benefit Plans
Number of benefit plans | plan	3
U.S. | Unfunded Plan
Postemployment Benefit Plans
Number of benefit plans | plan	3
U.K.
Weighted-average assumptions
Discount rate (as a percent)	4.80%	1.90%	1.50%
Expected rate of return (as a percent)	5%	2%	3.20%
U.K. | Funded Plan
Postemployment Benefit Plans
Number of benefit plans | plan	1
Transocean Plans | U.S.
Net periodic benefit costs, before tax
Interest cost	$ 65	$ 50	$ 47
Expected return on plan assets	(84)	(65)	(66)
Actuarial loss, net		5	11
Net periodic benefit costs (income)	(19)	(10)	(8)
Transocean Plans | Non-U.S. Plans
Net periodic benefit costs, before tax
Interest cost		6	6
Expected return on plan assets		(7)	(13)
Settlements and curtailments			(2)
Actuarial loss, net			1
Net periodic benefit costs (income)		$ (1)	$ (8)
Transocean Plans | U.K.
Net periodic benefit costs, before tax
Interest cost	9
Expected return on plan assets	(11)
Actuarial loss, net	$ 2
OPEB Plans
Weighted-average assumptions
Discount rate (as a percent)	4.92%	1.83%	1.21%
Net periodic benefit costs, before tax
Prior service gain, net	$ (2)	$ (2)	$ (2)
Net periodic benefit costs (income)	$ (2)	$ (2)	$ (2)

Postemployment Benefit Plans (F

Postemployment Benefit Plans (Funded) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 1,505	$ 2,085
Actuarial (gains) losses, net	43	(511)
Interest cost	74	56	$ 53
Currency exchange rate (gain) loss	11	(37)
Benefits paid	(89)	(88)
Projected benefit obligation, end of period	1,544	1,505	2,085
Change in plan assets
Fair value of plan assets, beginning of period	1,375	2,055
Actual return (loss) on plan assets	144	(550)
Currency exchange rate gain (loss)	12	(45)
Employer contributions	8	3	10
Benefits paid	(89)	(88)
Fair value of plan assets, end of period	1,450	1,375	2,055
Funded status, asset (liability), end of period	(94)	(130)
Balance sheet classification, end of period:
Pension asset, non-current	31	44
Pension liability, current	(4)	(4)
Pension liability, non-current	(121)	(170)
Accumulated other comprehensive loss (income), before taxes	228	234
Accumulated benefit obligation, end of period	1,544	1,505
Projected benefit obligation in excess of plan assets
Projected benefit obligation	1,336	1,317
Fair value of plan assets	1,211	1,143
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	231	239
Prior service cost (credit), net	(3)	(5)
Accumulated other comprehensive loss (income), before taxes	228	234
Transocean Plans
Change in plan assets
Fair value of plan assets, beginning of period	1,375
Fair value of plan assets, end of period	$ 1,450	$ 1,375
Transocean Plans | U.S.
Weighted average assumptions
Discount rate (as a percent)	4.88%	5.06%
Expected long-term rate of return (as a percent)	6.80%	6.41%
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 1,307	$ 1,724
Actuarial (gains) losses, net	32	(391)
Interest cost	65	50	47
Benefits paid	(76)	(76)
Projected benefit obligation, end of period	1,328	1,307	1,724
Change in plan assets
Fair value of plan assets, beginning of period	1,143	1,621
Actual return (loss) on plan assets	138	(403)
Employer contributions	6	1
Benefits paid	(76)	(76)
Fair value of plan assets, end of period	1,211	1,143	1,621
Funded status, asset (liability), end of period	(117)	(164)
Balance sheet classification, end of period:
Pension liability, current	(1)	(1)
Pension liability, non-current	(116)	(163)
Accumulated other comprehensive loss (income), before taxes	144	166
Accumulated benefit obligation, end of period	1,328	1,307
Projected benefit obligation in excess of plan assets
Projected benefit obligation	1,328	1,307
Fair value of plan assets	1,211	1,143
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	144	166
Accumulated other comprehensive loss (income), before taxes	144	166
Transocean Plans | Non-U.S. Plans
Change in projected benefit obligation
Projected benefit obligation, beginning of period	188	348
Actuarial (gains) losses, net		(119)
Interest cost		6	6
Currency exchange rate (gain) loss		(37)
Benefits paid		(10)
Projected benefit obligation, end of period		188	348
Change in plan assets
Fair value of plan assets, beginning of period	$ 232	434
Actual return (loss) on plan assets		(147)
Currency exchange rate gain (loss)		(45)
Benefits paid		(10)
Fair value of plan assets, end of period		232	434
Funded status, asset (liability), end of period		44
Balance sheet classification, end of period:
Pension asset, non-current		44
Accumulated other comprehensive loss (income), before taxes		76
Accumulated benefit obligation, end of period		$ 188
Transocean Plans | U.K.
Weighted average assumptions
Discount rate (as a percent)	4.50%	4.80%
Expected long-term rate of return (as a percent)	5.10%	5%
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 188
Actuarial (gains) losses, net	11
Interest cost	9
Currency exchange rate (gain) loss	11
Benefits paid	(11)
Projected benefit obligation, end of period	208	$ 188
Change in plan assets
Fair value of plan assets, beginning of period	232
Actual return (loss) on plan assets	6
Currency exchange rate gain (loss)	12
Benefits paid	(11)
Fair value of plan assets, end of period	239	232
Funded status, asset (liability), end of period	31
Balance sheet classification, end of period:
Pension asset, non-current	31
Accumulated other comprehensive loss (income), before taxes	90
Accumulated benefit obligation, end of period	208
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	88	74
Prior service cost (credit), net	2	2
Accumulated other comprehensive loss (income), before taxes	$ 90	$ 76
OPEB Plans
Weighted average assumptions
Discount rate (as a percent)	4.80%	4.92%
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 10	$ 13
Actuarial (gains) losses, net		(1)
Benefits paid	(2)	(2)
Projected benefit obligation, end of period	8	10	$ 13
Change in plan assets
Employer contributions	2	2
Benefits paid	(2)	(2)
Funded status, asset (liability), end of period	(8)	(10)
Balance sheet classification, end of period:
Pension liability, current	(3)	(3)
Pension liability, non-current	(5)	(7)
Accumulated other comprehensive loss (income), before taxes	(6)	(8)
Accumulated benefit obligation, end of period	8	10
Projected benefit obligation in excess of plan assets
Projected benefit obligation	8	10
Accumulated other comprehensive loss (income) that have not been recognized
Actuarial (gain) loss, net	(1)	(1)
Prior service cost (credit), net	(5)	(7)
Accumulated other comprehensive loss (income), before taxes	$ (6)	$ (8)

Postemployment Benefit Plans (A

Postemployment Benefit Plans (Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Fair value of plan assets
Total investments	$ 1,450	$ 1,375	$ 2,055
Funding contributions
Employer contributions	8	$ 3	10
Expected defined plan contributions next year	4
Projected pension benefits payments
2024	93
2025	94
2026	93
2027	93
2028	94
2029-2033	$ 486
U.S.
Weighted-average target allocations of the investments
Total target allocation percentage	100%
Total actual allocation percentage	100%	100%
U.S. | Equity securities
Weighted-average target allocations of the investments
Total target allocation percentage	38%
Total actual allocation percentage	37%	38%
U.S. | Fixed income securities
Weighted-average target allocations of the investments
Total target allocation percentage	62%
Total actual allocation percentage	62%	61%
U.S. | Other investments
Weighted-average target allocations of the investments
Total actual allocation percentage	1%	1%
U.K.
Weighted-average target allocations of the investments
Total target allocation percentage	100%	100%
Total actual allocation percentage	100%	100%
U.K. | Equity securities
Weighted-average target allocations of the investments
Total target allocation percentage	20%	20%
Total actual allocation percentage	21%	24%
U.K. | Fixed income securities
Weighted-average target allocations of the investments
Total target allocation percentage	73%	80%
Total actual allocation percentage	72%	74%
U.K. | Other investments
Weighted-average target allocations of the investments
Total target allocation percentage	7%
Total actual allocation percentage	7%	2%
Transocean Plans
Fair value of plan assets
Total investments	$ 1,450	$ 1,375
Funding contributions
Expected defined plan contributions next year	1
Transocean Plans | Significant observable inputs
Fair value of plan assets
Total investments	1,208	1,141
Transocean Plans | Significant other observable inputs
Fair value of plan assets
Total investments	242	234
Transocean Plans | Mutual funds
Fair value of plan assets
Total investments	1,427	1,365
Transocean Plans | Mutual funds | Significant observable inputs
Fair value of plan assets
Total investments	1,201	1,131
Transocean Plans | Mutual funds | Significant other observable inputs
Fair value of plan assets
Total investments	226	234
Transocean Plans | U.S. equity funds
Fair value of plan assets
Total investments	316	301
Transocean Plans | U.S. equity funds | Significant observable inputs
Fair value of plan assets
Total investments	316	301
Transocean Plans | Non-U.S. equity funds
Fair value of plan assets
Total investments	190	193
Transocean Plans | Non-U.S. equity funds | Significant observable inputs
Fair value of plan assets
Total investments	139	132
Transocean Plans | Non-U.S. equity funds | Significant other observable inputs
Fair value of plan assets
Total investments	51	61
Transocean Plans | Bond funds
Fair value of plan assets
Total investments	921	871
Transocean Plans | Bond funds | Significant observable inputs
Fair value of plan assets
Total investments	746	698
Transocean Plans | Bond funds | Significant other observable inputs
Fair value of plan assets
Total investments	175	173
Transocean Plans | Other investments
Fair value of plan assets
Total investments	23
Transocean Plans | Other investments | Significant observable inputs
Fair value of plan assets
Total investments	7
Transocean Plans | Other investments | Significant other observable inputs
Fair value of plan assets
Total investments	16
Transocean Plans | Cash and money market funds
Fair value of plan assets
Total investments	7	10
Transocean Plans | Cash and money market funds | Significant observable inputs
Fair value of plan assets
Total investments	7	10
Transocean Plans | Synthetic leveraged credit fund
Fair value of plan assets
Total investments	16
Transocean Plans | Synthetic leveraged credit fund | Significant other observable inputs
Fair value of plan assets
Total investments	16
Transocean Plans | U.S.
Fair value of plan assets
Total investments	1,211	1,143	1,621
Funding contributions
Employer contributions	6	1
Projected pension benefits payments
2024	84
2025	84
2026	84
2027	85
2028	85
2029-2033	427
Transocean Plans | U.S. | Significant observable inputs
Fair value of plan assets
Total investments	1,207	1,137
Transocean Plans | U.S. | Significant other observable inputs
Fair value of plan assets
Total investments	4	6
Transocean Plans | U.S. | Mutual funds
Fair value of plan assets
Total investments	1,205	1,137
Transocean Plans | U.S. | Mutual funds | Significant observable inputs
Fair value of plan assets
Total investments	1,201	1,131
Transocean Plans | U.S. | Mutual funds | Significant other observable inputs
Fair value of plan assets
Total investments	4	6
Transocean Plans | U.S. | U.S. equity funds
Fair value of plan assets
Total investments	316	301
Transocean Plans | U.S. | U.S. equity funds | Significant observable inputs
Fair value of plan assets
Total investments	316	301
Transocean Plans | U.S. | Non-U.S. equity funds
Fair value of plan assets
Total investments	139	136
Transocean Plans | U.S. | Non-U.S. equity funds | Significant observable inputs
Fair value of plan assets
Total investments	139	132
Transocean Plans | U.S. | Non-U.S. equity funds | Significant other observable inputs
Fair value of plan assets
Total investments		4
Transocean Plans | U.S. | Bond funds
Fair value of plan assets
Total investments	750	700
Transocean Plans | U.S. | Bond funds | Significant observable inputs
Fair value of plan assets
Total investments	746	698
Transocean Plans | U.S. | Bond funds | Significant other observable inputs
Fair value of plan assets
Total investments	4	2
Transocean Plans | U.S. | Other investments
Fair value of plan assets
Total investments	6
Transocean Plans | U.S. | Other investments | Significant observable inputs
Fair value of plan assets
Total investments	6
Transocean Plans | U.S. | Cash and money market funds
Fair value of plan assets
Total investments	6	6
Transocean Plans | U.S. | Cash and money market funds | Significant observable inputs
Fair value of plan assets
Total investments	6	6
Transocean Plans | Non-U.S. Plans
Fair value of plan assets
Total investments		232	$ 434
Transocean Plans | U.K.
Fair value of plan assets
Total investments	239	232
Projected pension benefits payments
2024	6
2025	7
2026	8
2027	8
2028	9
2029-2033	58
Transocean Plans | U.K. | Significant observable inputs
Fair value of plan assets
Total investments	1	4
Transocean Plans | U.K. | Significant other observable inputs
Fair value of plan assets
Total investments	238	228
Transocean Plans | U.K. | Mutual funds
Fair value of plan assets
Total investments	222	228
Transocean Plans | U.K. | Mutual funds | Significant other observable inputs
Fair value of plan assets
Total investments	222	228
Transocean Plans | U.K. | Non-U.S. equity funds
Fair value of plan assets
Total investments	51	57
Transocean Plans | U.K. | Non-U.S. equity funds | Significant other observable inputs
Fair value of plan assets
Total investments	51	57
Transocean Plans | U.K. | Bond funds
Fair value of plan assets
Total investments	171	171
Transocean Plans | U.K. | Bond funds | Significant other observable inputs
Fair value of plan assets
Total investments	171	171
Transocean Plans | U.K. | Other investments
Fair value of plan assets
Total investments	17
Transocean Plans | U.K. | Other investments | Significant observable inputs
Fair value of plan assets
Total investments	1
Transocean Plans | U.K. | Other investments | Significant other observable inputs
Fair value of plan assets
Total investments	16
Transocean Plans | U.K. | Cash and money market funds
Fair value of plan assets
Total investments	1	4
Transocean Plans | U.K. | Cash and money market funds | Significant observable inputs
Fair value of plan assets
Total investments	1	4
Transocean Plans | U.K. | Synthetic leveraged credit fund
Fair value of plan assets
Total investments	16
Transocean Plans | U.K. | Synthetic leveraged credit fund | Significant other observable inputs
Fair value of plan assets
Total investments	16
OPEB Plans
Funding contributions
Employer contributions	2	$ 2
Expected defined plan contributions next year	3
Projected pension benefits payments
2024	3
2025	3
2026	1
2029-2033	$ 1

Income Taxes (Expense) (Details

Income Taxes (Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes
Effective tax rate	(1.40%)	(10.40%)	(25.70%)
Components of provision (benefit) for income taxes
Current tax expense (benefit)	$ (5)	$ 13	$ (7)
Deferred tax expense	18	46	128
Income tax expense	$ 13	$ 59	$ 121

Income Taxes (Reconciliation) (

Income Taxes (Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income tax expense reconciliation
Swiss holding company federal statutory rate (as a percent)	7.83%
Income tax benefit at Swiss federal statutory rate	$ (74)	$ (44)	$ (36)
Earnings subject to rates different than the Swiss federal statutory rate	129	52	78
Deemed profits taxes	11	10	17
Withholding taxes	5	12	10
Changes in unrecognized tax benefits, net	(37)	2	(43)
Changes in valuation allowance	(23)	79	1,167
Swiss Federal Act on Tax Reform and AHV Financing		96	(1,095)
Audit settlement		12
Changes due to organizational restructuring		(162)	16
Losses on impairment			5
Other, net	2	2	2
Income tax expense	13	$ 59	$ 121
Swiss historic depreciation and financing asset costs	$ 1,210

Income Taxes (Deferred) (Detail

Income Taxes (Deferred) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income taxes
Changes in valuation allowance	$ (23)	$ 79	$ 1,167
Deferred tax assets
Swiss historic depreciation and financing asset costs	1,210
Net operating loss carryforwards	1,264
Interest expense limitation	87
United Kingdom charter limitation	53
Accrued expenses	47
Tax credits	4
Accrued payroll expenses not currently deductible	16
Loss contingencies	4
Other	54
Valuation allowance	(1,884)	(1,910)
Total deferred tax assets, net of allowance	855
Deferred tax liabilities
Depreciation	(1,342)
Other	(9)
Total deferred tax liabilities	(1,351)
Deferred tax assets (liabilities), net	(496)
U.S. foreign tax credit carryforwards	4	11
NOLs that are not subject to expiration dates	585
NOLs that are subject to expiration dates	855
Reconciliation of unrecognized tax benefits, excluding interest and penalties
Balance, beginning of period	444	402	378
Additions for current year tax positions	45	28	28
Additions for prior year tax positions	5	62	46
Reductions related to statute of limitation expirations and changes in law	(14)	(13)	(19)
Reductions due to settlements	(5)	(5)	(31)
Reductions for prior year tax positions	(26)	(30)
Balance, end of period	449	444	402
Unrecognized tax benefits
Unrecognized tax benefits, excluding interest and penalties	449	444	402
Interest and penalties	9	27
Unrecognized tax benefits, including interest and penalties	458	471
Interest and penalties related to unrecognized tax benefits recognized as a component of income tax expense	(18)	6	$ 8
Unrecognized benefits netted against NOL deferred tax assets	411
Amount if recognized that would impact tax rate	47
Swiss TRAF
Income taxes
Changes in valuation allowance	1,100	1,100
Deferred tax assets
Total deferred tax assets, net of allowance	1,210	1,230
Deferred tax liabilities
Total deferred tax liabilities	$ (264)	$ (226)

Income Taxes (Tax Returns) (Det

Income Taxes (Tax Returns) (Details) - 12 months ended Dec. 31, 2023 - Brazil R$ in Millions, $ in Millions	BRL (R$)	USD ($)
Corporate income tax
Income Tax Examination
Net adjustments of additional taxes, including interest and penalties	R$ 698	$ 144
Indirect tax
Income Tax Examination
Net adjustments of additional taxes, including interest and penalties	R$ 90	$ 19

Loss Per Share (Details)

Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings per share
Net loss attributable to controlling interest	$ (954)	$ (621)	$ (592)
Weighted-average shares for per share calculation, basic (in shares)	768	699	637
Weighted-average shares for per share calculation, diluted (in shares)	768	699	637
Loss per share, basic (in dollars per share)	$ (1.24)	$ (0.89)	$ (0.93)
Loss per share, diluted (in dollars per share)	$ (1.24)	$ (0.89)	$ (0.93)
Exchangeable bonds
Earnings per share
Securities excluded from earnings per share calculation (in shares)	150.8	128.1	104.4
Share-based awards
Earnings per share
Securities excluded from earnings per share calculation (in shares)	18.6	15.5	12.6
Warrant
Earnings per share
Securities excluded from earnings per share calculation (in shares)	10.2

Commitments and Contingencies_2

Commitments and Contingencies (PurchOb) (Details) $ in Millions	Dec. 31, 2023 USD ($)
Supply agreement
Future Purchase obligations
2024	$ 131
2025	145
2026	149
2027	121
2028	73
Thereafter	109
Total	728
New builds
Future Purchase obligations
2024	19
2025	2
Total	$ 21

Commitments and Contingencies_3

Commitments and Contingencies (Letters of credit and surety bonds) (Details) - Letters of credit and surety bonds - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Letters of credit and surety bonds
Outstanding letters of credit	$ 16	$ 8
Surety bonds outstanding	198	161
Aggregate cash collateral	$ 7	$ 7

Commitments and Contingencies_4

Commitments and Contingencies (Legal proceedings) (Details)	Dec. 31, 2023 lawsuit
Asbestos litigation
Contingencies
Number of claims	257

Equity (Share Issuance) (Detail

Equity (Share Issuance) (Details) - USD ($) shares in Millions, $ in Millions		1 Months Ended				12 Months Ended
	Sep. 15, 2023	Oct. 31, 2023	Sep. 30, 2023	Aug. 31, 2022	Jun. 30, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity
Shares issued upon conversion (in shares)		26.5				65.1
Proceeds from issuance of shares, net of issue costs							$ 263	$ 158
ATM Program
Equity
Maximum value shares to be issued				$ 435	$ 400
Proceeds from issuance of shares, net of issue costs							$ 263	$ 158
Issuance of shares (in shares)							61	36.1
Liquila
Equity
Newly issued shares in asset acquisition (in shares)	11.9		11.9
Value shares issued in asset acquisition	$ 99		$ 99			$ 99

Equity (Warrants) (Details)

Equity (Warrants) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
	Sep. 30, 2022	Dec. 31, 2022
Equity
Number of warrants issued to subscribe	22.2
Exercise price	$ 3.71
Stock price trigger	$ 10
Estimated fair value	$ 16	$ 16

Equity (Shares held by subsidia

Equity (Shares held by subsidiaries) (Details) shares in Millions	Dec. 31, 2023 subsidiary shares	Dec. 31, 2022 shares
Equity
Number of subsidiaries to whom shares were issued | subsidiary	1
Number of shares held by subsidiary | shares	34.7	75.4

Share-Based Compensation (Detai

Share-Based Compensation (Details) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) shares
Share Based Compensation
Shares authorized under the plan	115.7
Shares available for grant under the plan	31.2
Total unrecognized compensation costs related to all unvested share based awards | $	$ 42
Weighted average period over compensation costs are expected to be recognized	1 year 8 months 19 days
Service awards
Share Based Compensation
Vesting period	3 years
General term of awards after they are vested	7 years
Performance awards
Share Based Compensation
Measurement period	3 years

Share-Based Compensation (Non o

Share-Based Compensation (Non options) (Details) - Restricted shares - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Service awards
Equity instruments other than options activity
Outstanding at the beginning of the period (in shares)	12,047,500
Granted (in shares)	3,744,049	6,768,943	6,148,361
Vested (in shares)	(6,200,155)	(5,075,374)	(4,368,749)
Forfeited (in shares)	(31,386)
Outstanding at the end of the period (in shares)	9,560,008	12,047,500
Weighted-average grant-date fair value per share
Outstanding at the beginning of the period (in dollars per share)	$ 3.25
Granted (in dollars per share)	7.23	$ 3.60	$ 3.56
Vested (in dollars per share)	2.94
Forfeited (in dollars per share)	3.56
Outstanding at the end of the period (in dollars per share)	$ 5.01	$ 3.25
Additional disclosure
Total grant date fair value	$ 18	$ 18	$ 16
Performance awards
Equity instruments other than options activity
Outstanding at the beginning of the period (in shares)	6,545,369
Granted (in shares)	1,912,292	3,519,857	3,025,512
Vested (in shares)	(3,025,512)
Outstanding at the end of the period (in shares)	5,432,149	6,545,369
Weighted-average grant-date fair value per share
Outstanding at the beginning of the period (in dollars per share)	$ 3.81
Granted (in dollars per share)	6.74	$ 3.91	$ 3.70
Vested (in dollars per share)	3.70
Outstanding at the end of the period (in dollars per share)	$ 4.91	$ 3.81
Additional disclosure
Total grant date fair value	$ 11	$ 5	$ 11

Share-Based Compensation (Optio

Share-Based Compensation (Options) (Details) - Service awards - Employee Stock Option [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock option activity
Outstanding at the beginning of the period (in shares)	4,175,520
Forfeited (in shares)	(25,017)
Expired (in shares)	(66,574)
Outstanding at the end of the period (in shares)	4,083,929	4,175,520
Vested and exercisable at the end of the period (in shares)	4,083,929
Weighted-average exercise price per share
Outstanding at the beginning of the period (in dollars per share)	$ 10.63
Forfeited (in dollars per share)	59.30
Expired (in dollars per share)	59.30
Outstanding at the end of the period (in dollars per share)	9.54	$ 10.63
Vested and exercisable at the end of the period (in dollars per share)	$ 9.54
Additional disclosure
Weighted-average remaining contractual term, outstanding	3 years 11 months 1 day	4 years 9 months 25 days
Weighted-average remaining contractual term, vested and exercisable at the end of the period	3 years 11 months 1 day
Total grant-date fair value of awards vested		$ 4	$ 9
Unvested stock options outstanding (in shares)	0	0

Supplemental Balance Sheet In_3

Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Other current liabilities
Accrued employee benefits and payroll-related liabilities	$ 145	$ 156
Accrued interest	146	113
Accrued taxes, other than income	47	41
Finance lease liability	$ 43	$ 40
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Total other current liabilities	Total other current liabilities
Operating lease liabilities	$ 12	$ 7
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Total other current liabilities	Total other current liabilities
Deferred revenues	$ 165	$ 124
Contingent liabilities	116	58
Other	7
Total other current liabilities	681	539
Other long-term liabilities
Postemployment benefit plan obligations	121	170
Finance lease liability	$ 276	$ 323
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Total other long-term liabilities	Total other long-term liabilities
Operating lease liabilities	$ 108	$ 100
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Total other long-term liabilities	Total other long-term liabilities
Income taxes payable	$ 80	$ 129
Deferred revenues	233	204
Other	40	39
Total other long-term liabilities	$ 858	$ 965

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) shares in Millions, $ in Millions		1 Months Ended								12 Months Ended
	Sep. 15, 2023	Oct. 31, 2023	Sep. 30, 2023	Jul. 31, 2023	Apr. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Feb. 28, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 30, 2022
Changes in other operating assets and liabilities
(Increase) decrease in accounts receivable										$ (99)	$ (15)	$ 137
Increase in other assets										(98)	(12)	(13)
Increase (decrease) in accounts payable and other current liabilities										135	8	(52)
Decrease in other long-term liabilities										(7)	(2)	(3)
Change in income taxes receivable / payable, net										(36)	(42)	(17)
Change in receivables from / payables to affiliates, net										(8)	(12)	(15)
Net change in operating assets and liabilities										(113)	(75)	37
Certain cash operating activities
Cash payments for interest										408	355	429
Cash payments for income taxes										41	66	57
Non-cash investing and financing activities
Capital additions accrued at end of period										36	31	28
Finance lease installments settled with credits issued to customer										$ 44	41
Shares issued in exchanges of exchangeable bonds										434
Warrants issued in exchange transactions						$ 5					5
Shares issued upon conversion (in shares)		26.5								65.1
Debt issued in exchange transactions											112	294
Number of warrants issued to subscribe							22.2
Orion/Transocean Norge
Non-cash investing and financing activities
Exchange										$ 37
Exchanged
Non-cash investing and financing activities
Exchange											110	260
Warrants issued in exchange transactions						5					5
Debt issued in exchange transactions											112	294
2022 Private Exchange
Non-cash investing and financing activities
Warrants issued in exchange transactions						$ 5					$ 5
Number of warrants issued to subscribe						6.7	6.7				6.7
4.50% Shipyard Loan due June 2027
Non-cash investing and financing activities
Capital additions acquired in exchange for debt						$ 82		$ 300			$ 382
Debt instrument face value						$ 439		$ 349			439		$ 90
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Non-cash investing and financing activities
Exchange											105
Debt instrument face value							$ 188
Debt issued in exchange transactions											$ 112
Number of warrants issued to subscribe							15.5
4.625% Senior Guaranteed Exchangeable Bonds due September 2029 | 2022 Private Exchange
Non-cash investing and financing activities
Debt instrument face value							$ 300
Debt issued in exchange transactions							$ 73
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Non-cash investing and financing activities
Exchange												260
Debt issued in exchange transactions									$ 294			$ 294
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Non-cash investing and financing activities
Shares issued upon conversion (in shares)				4	34.6
Liquila
Non-cash investing and financing activities
Acquisition of outstanding ownership interests in exchange for shares	$ 99		$ 99							$ 99
Newly issued shares in asset acquisition (in shares)	11.9		11.9

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Carrying amount
Financial instruments
Cash and cash equivalents	$ 762	$ 683
Restricted cash and cash equivalents	233	308
Long-term loans receivable from unconsolidated affiliates	6	41
Total debt	7,413	7,347
Fair value
Financial instruments
Cash and cash equivalents	762	683
Restricted cash and cash equivalents	233	308
Long-term loans receivable from unconsolidated affiliates	6	43
Total debt	$ 7,308	$ 6,412

Risk Concentration (Details)

Risk Concentration (Details)	12 Months Ended
	Dec. 31, 2023 employee
Labor Agreements
Number of employees	5,800
Number of employees engaged through contract labor providers	370
Unionized Employees | Workforce Subject to Collective Bargaining
Labor Agreements
Percentage of concentration	42%

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for credit losses
Reserves and allowances deducted from asset accounts
Balance, beginning of period	$ 2	$ 2	$ 2
Additions: charged to cost and expenses		0
Additions: charged to other accounts		0
Deductions		0
Balance, end of period	2	2	2
Allowance for excess materials and supplies
Reserves and allowances deducted from asset accounts
Balance, beginning of period	199	183	143
Additions: charged to cost and expenses	6	16	43
Additions: charged to other accounts		0
Deductions	(7)	0	(3)
Balance, end of period	198	199	183
Valuation allowance on deferred tax assets
Reserves and allowances deducted from asset accounts
Balance, beginning of period	1,910	1,820	685
Additions: charged to cost and expenses		79	1,167
Additions: charged to other accounts		11
Deductions	(26)	0	(32)
Balance, end of period	$ 1,884	$ 1,910	$ 1,820

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss)	$ (954)	$ (621)	$ (592)

Insider Trading Arrangements

Insider Trading Arrangements - Keelan Adamson	3 Months Ended
	Dec. 31, 2023 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On December 19, 2023, Keelan Adamson, President and Chief Operating Officer of the Company, adopted a Rule 10b5-1 trading arrangement (as such term is defined under Item 408(a) of Regulation S-K) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) for the sale of up to 211,308 shares of Transocean Ltd. (the “Plan”).  Sales may not commence under the Plan until March 26, 2024 at the earliest and, for certain of the shares, only at specified market prices.  Unless earlier terminated in accordance with the terms and conditions of the Plan, the Plan expires on December 19, 2024
Name	Keelan Adamson
Title	President and Chief Operating Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	December 19, 2023
Aggregate Available	211,308