Transocean (RIG) 10-Q 1 Aug 23 2023 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2023	Jul. 25, 2023
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 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		766,655,180
Entity Central Index Key	0001451505
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false
Title of 12(b) Security	Shares
Trading Symbol	RIG
Security Exchange Name	NYSE

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating revenues
Contract drilling revenues	$ 729	$ 692	$ 1,378	$ 1,278
Revenue from Contract with Customer, Product and Service [Extensible List]	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember
Costs and expenses
Operating and maintenance	$ 484	$ 433	$ 893	$ 845
Cost, Product and Service [Extensible List]	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember	us-gaap:OilAndGasServiceMember
Depreciation and amortization	$ 186	$ 184	$ 368	$ 367
General and administrative	48	43	93	85
Total costs and expenses	718	660	1,354	1,297
Loss on impairment of assets	(53)		(53)
Loss on disposal of assets, net		(4)	(170)	(3)
Operating income (loss)	(42)	28	(199)	(22)
Other income (expense), net
Interest income	11	4	30	6
Interest expense, net of amounts capitalized	(168)	(100)	(417)	(202)
Loss on retirement of debt			(32)
Other, net	18	3	23	4
Total other income (expense), net	(139)	(93)	(396)	(192)
Loss before income tax expense (benefit)	(181)	(65)	(595)	(214)
Income tax expense (benefit)	(16)	3	35	29
Net loss	(165)	(68)	(630)	(243)
Net loss attributable to controlling interest	$ (165)	$ (68)	$ (630)	$ (243)
Loss per share, basic (in dollars per share)	$ (0.22)	$ (0.10)	$ (0.85)	$ (0.36)
Loss per share, diluted (in dollars per share)	$ (0.22)	$ (0.10)	$ (0.85)	$ (0.36)
Weighted-average shares, basic (in shares)	761	692	745	678
Weighted-average shares, diluted (in shares)	761	692	745	678

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (165)	$ (68)	$ (630)	$ (243)
Net loss attributable to controlling interest	(165)	(68)	(630)	(243)
Components of net periodic benefit costs before reclassifications			(11)	(11)
Components of net periodic benefit costs reclassified to net loss		1		2
Other comprehensive income (loss) before income taxes		1	(11)	(9)
Other comprehensive income (loss)		1	(11)	(9)
Other comprehensive income (loss) attributable to controlling interest		1	(11)	(9)
Total comprehensive loss	(165)	(67)	(641)	(252)
Total comprehensive loss attributable to controlling interest	$ (165)	$ (67)	$ (641)	$ (252)

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Assets
Cash and cash equivalents	$ 821	$ 683
Accounts receivable, net of allowance of $3 and $2 at June 30, 2023 and December 31, 2022, respectively	523	485
Materials and supplies, net of allowance of $202 and $199 at June 30, 2023 and December 31, 2022, respectively	397	388
Restricted cash and cash equivalents	213	308
Other current assets	281	144
Total current assets	2,235	2,008
Property and equipment	23,527	24,217
Less accumulated depreciation	(6,607)	(6,748)
Property and equipment, net	16,920	17,469
Contract intangible assets	19	56
Deferred tax assets, net	45	13
Other assets	994	890
Total assets	20,213	20,436
Liabilities and equity
Accounts payable	285	281
Accrued income taxes	16	19
Debt due within one year	293	719
Other current liabilities	547	539
Total current liabilities	1,141	1,558
Long-term debt	7,154	6,628
Deferred tax liabilities, net	552	493
Other long-term liabilities	961	965
Total long-term liabilities	8,667	8,086
Commitments and contingencies
Shares, CHF 0.10 par value, 1,021,294,549 authorized, 142,362,093 conditionally authorized, 831,845,482 issued and 766,655,180 outstanding at June 30, 2023, and 905,093,509 authorized, 142,362,675 conditionally authorized, 797,244,753 issued and 721,888,427 outstanding at December 31, 2022	76	71
Additional paid-in capital	14,233	13,984
Accumulated deficit	(3,709)	(3,079)
Accumulated other comprehensive loss	(196)	(185)
Total controlling interest shareholders' equity	10,404	10,791
Noncontrolling interest	1	1
Total equity	10,405	10,792
Total liabilities and equity	$ 20,213	$ 20,436

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) $ in Millions	Jun. 30, 2023 USD ($) shares	Jun. 30, 2023 SFr / shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2022 SFr / shares
CONDENSED CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts | $	$ 3		$ 2
Materials and supplies, allowance for obsolescence | $	$ 202		$ 199
Shares, CHF par value (in Swiss francs per share) | SFr / shares		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	831,845,482		797,244,753
Shares, outstanding	766,655,180		721,888,427

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ 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, 2021	$ 11,205	$ 64	$ 13,683	$ (2,458)	$ (84)	$ 1	$ 11,206
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss							(252)
Total comprehensive loss attributable to controlling interest	(252)						(252)
Share-based compensation	15		15				15
Issuance of shares	206	5	201				206
Net Income (Loss)				(243)			(243)
Other comprehensive income (loss) attributable to controlling interest					(9)		(9)
Balance at Jun. 30, 2022	11,174	69	13,899	(2,701)	(93)	1	11,175
Balance at Mar. 31, 2022	11,130	67	13,790	(2,633)	(94)	1	11,131
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss							(67)
Total comprehensive loss attributable to controlling interest	(67)						(67)
Share-based compensation	8		8				8
Issuance of shares	103	2	101				103
Net Income (Loss)				(68)			(68)
Other comprehensive income (loss) attributable to controlling interest					1		1
Balance at Jun. 30, 2022	11,174	69	13,899	(2,701)	(93)	1	11,175
Balance at Dec. 31, 2022	10,791	71	13,984	(3,079)	(185)	1	10,792
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss							(641)
Total comprehensive loss attributable to controlling interest	(641)						(641)
Share-based compensation	20		20				20
Issuance of shares	234	5	229				234
Net Income (Loss)				(630)			(630)
Other comprehensive income (loss) attributable to controlling interest					(11)		(11)
Balance at Jun. 30, 2023	10,404	76	14,233	(3,709)	(196)	1	10,405
Balance at Mar. 31, 2023	10,324	72	13,992	(3,544)	(196)	1	10,325
Increase (Decrease) in Shareholders' Equity
Total comprehensive loss							(165)
Total comprehensive loss attributable to controlling interest	(165)						(165)
Share-based compensation	11		11				11
Issuance of shares	234	4	230				234
Net Income (Loss)				(165)			(165)
Balance at Jun. 30, 2023	$ 10,404	$ 76	$ 14,233	$ (3,709)	$ (196)	$ 1	$ 10,405

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities
Net loss	$ (630)	$ (243)
Adjustments to reconcile to net cash provided by operating activities:
Contract intangible asset amortization	37	59
Depreciation and amortization	368	367
Share-based compensation expense	20	15
Loss on impairment of assets	53
Loss on disposal of assets, net	170	3
Fair value adjustment to bifurcated compound exchange feature	179
Loss on retirement of debt	32
Deferred income tax expense	27	25
Other, net	46	32
Changes in deferred revenues, net	27	(31)
Changes in deferred costs, net	(37)	13
Changes in other operating assets and liabilities, net	(182)	(200)
Net cash provided by operating activities	110	40
Cash flows from investing activities
Capital expenditures	(157)	(221)
Investments in equity of unconsolidated affiliates	(10)	(19)
Proceeds from disposal of assets, net	4	4
Net cash used in investing activities	(163)	(236)
Cash flows from financing activities
Repayments of debt	(1,568)	(257)
Proceeds from issuance of debt, net of issue costs	1,665
Proceeds from issuance of shares, net of issue costs		206
Other, net	(1)	(4)
Net cash provided by (used in) financing activities	96	(55)
Net increase (decrease) in unrestricted and restricted cash and cash equivalents	43	(251)
Unrestricted and restricted cash and cash equivalents, beginning of period	991	1,412
Unrestricted and restricted cash and cash equivalents, end of period	$ 1,034	$ 1,161

Business

Business	6 Months Ended
	Jun. 30, 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 June 30, 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 June 30, 2023, we held a noncontrolling ownership interest in a company that is constructing one ultra-deepwater drillship.

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2023
Significant Accounting Policies
Significant Accounting Policies	Note 2—Significant Accounting Policies Presentation Form 10-K filed on February 23, 2023 Accounting estimates Fair value measurements

Unconsolidated Affiliates

Unconsolidated Affiliates	6 Months Ended
	Jun. 30, 2023
Unconsolidated Affiliates
Unconsolidated Affiliates	Note 3—Unconsolidated Affiliates We hold noncontrolling equity investments in various unconsolidated companies . Ocean Rig Olympia Note 5—Long-lived assets Deepwater Aquila In the three and six months ended June 30, 2023, we incurred costs of approximately $10 million and $50 million, respectively, primarily for contract preparation and upgrade shipyard costs for Transocean Norge Orion. At June 30, 2023 and December 31, 2022, our accounts receivable from affiliates was $90 million and $32 million, respectively, recorded in other current assets and our accounts payable to affiliates was $17 million and $2 million, respectively, recorded in accounts payable.

Revenues

Revenues	6 Months Ended
	Jun. 30, 2023
Revenues
Revenues	Note 4—Revenues Overview Disaggregation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ ​ 2023 ​ 2022 2023 ​ 2022 ​ Ultra- Harsh ​ ​ Ultra- Harsh ​ Ultra- Harsh ​ ​ Ultra- Harsh ​ ​ deepwater environment ​ ​ deepwater environment ​ deepwater environment ​ ​ deepwater environment ​ ​ floaters floaters Total ​ floaters floaters Total floaters floaters Total ​ floaters floaters Total U.S. $ 365 ​ $ — ​ $ 365 ​ $ 253 ​ $ — ​ $ 253 $ 717 ​ $ — ​ $ 717 ​ $ 521 ​ $ — ​ $ 521 Norway ​ ​ — ​ ​ 142 ​ ​ 142 ​ ​ — ​ ​ 241 ​ ​ 241 ​ ​ — ​ ​ 290 ​ ​ 290 ​ ​ — ​ ​ 434 ​ ​ 434 ​ Other countries (a) ​ ​ 171 ​ ​ 51 ​ ​ 222 ​ ​ 198 ​ ​ — ​ ​ 198 ​ ​ 303 ​ ​ 68 ​ ​ 371 ​ ​ 320 ​ ​ 3 ​ ​ 323 ​ Total contract drilling revenues $ 536 ​ $ 193 ​ $ 729 ​ $ 451 ​ $ 241 ​ $ 692 $ 1,020 ​ $ 358 ​ $ 1,378 ​ $ 841 ​ $ 437 ​ $ 1,278 (a) The aggregate contract drilling revenues earned in other countries that individually represented less than 10 percent of total contract drilling revenues. Contract liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ ​ 2023 2022 Deferred contract revenues, recorded in other current liabilities $ 128 ​ $ 124 ​ Deferred contract revenues, recorded in other long-term liabilities ​ ​ 227 ​ ​ 204 ​ Total contract liabilities $ 355 ​ $ 328 ​ Significant changes in contract liabilities were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ June 30, ​ ​ 2023 2022 Total contract liabilities, beginning of period ​ $ 328 ​ $ 348 ​ Decrease due to recognition of revenues for goods and services ​ ​ (104) ​ ​ (61) ​ Increase due to goods and services transferred over time ​ ​ 131 ​ ​ 30 ​ Total contract liabilities, end of period ​ $ 355 ​ $ 317 ​ ​ Pre-operating costs

Long- Lived Assets

Long- Lived Assets	6 Months Ended
	Jun. 30, 2023
Long-Lived Assets
Long -Lived Assets	Note 5—Long-Lived Assets Construction work in progress ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ June 30, ​ ​ 2023 2022 Construction work in progress, beginning of period $ 1,195 ​ $ 1,017 ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital expenditures ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ 114 ​ ​ 193 ​ Other equipment and construction projects ​ ​ 43 ​ ​ 28 ​ Total capital expenditures ​ ​ 157 ​ ​ 221 ​ Non-cash capital additions financed under Shipyard Loan ​ ​ — ​ ​ 300 ​ Changes in accrued capital additions ​ ​ (6) ​ ​ (16) ​ ​ ​ ​ ​ ​ ​ ​ ​ Property and equipment placed into service ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ (1,157) ​ ​ — ​ Other equipment and construction projects ​ ​ (20) ​ ​ (26) ​ Construction work in progress, end of period $ 169 ​ $ 1,496 ​ ​ Impairment Paul B. Loyd, Jr. Transocean Leader Disposal Ocean Rig Olympia Note 3—Unconsolidated affiliates Assets held for sale Paul B. Loyd, Jr. Transocean Leader

Debt

Debt	6 Months Ended
	Jun. 30, 2023
Debt
Debt	Note 6—Debt Overview Outstanding debt ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal amount ​ ​ Carrying amount ​ ​ June 30, ​ December 31, ​ June 30, ​ December 31, ​ 2023 2022 2023 2022 0.50% Exchangeable Senior Bonds due January 2023 ​ $ — ​ $ 49 ​ ​ $ — ​ $ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ ​ — ​ ​ 352 ​ ​ ​ — ​ ​ 350 ​ 7.75% Senior Secured Notes due October 2024 ​ ​ — ​ ​ 240 ​ ​ ​ — ​ ​ 238 ​ 6.25% Senior Secured Notes due December 2024 ​ ​ — ​ ​ 250 ​ ​ ​ — ​ ​ 248 ​ 6.125% Senior Secured Notes due August 2025 ​ ​ — ​ ​ 336 ​ ​ ​ — ​ ​ 332 ​ 7.25% Senior Notes due November 2025 ​ ​ 354 ​ ​ 354 ​ ​ ​ 351 ​ ​ 351 ​ 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ 294 ​ ​ 294 ​ ​ ​ 274 ​ ​ 271 ​ 7.50% Senior Notes due January 2026 ​ ​ 569 ​ ​ 569 ​ ​ ​ 567 ​ ​ 566 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ 25 ​ ​ 238 ​ ​ ​ 27 ​ ​ 265 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ ​ 687 ​ ​ 687 ​ ​ ​ 973 ​ ​ 1,008 ​ 6.875% Senior Secured Notes due February 2027 ​ ​ 447 ​ ​ 482 ​ ​ ​ 443 ​ ​ 477 ​ 8.00% Senior Notes due February 2027 ​ ​ 612 ​ ​ 612 ​ ​ ​ 609 ​ ​ 608 ​ 7.45% Notes due April 2027 ​ ​ 52 ​ ​ 52 ​ ​ ​ 52 ​ ​ 52 ​ 8.00% Debentures due April 2027 ​ ​ 22 ​ ​ 22 ​ ​ ​ 22 ​ ​ 22 ​ 4.50% Shipyard Loans due September 2027 ​ ​ 439 ​ ​ 439 ​ ​ ​ 396 ​ ​ 389 ​ 8.375% Senior Secured Notes due February 2028 ​ ​ 525 ​ ​ — ​ ​ ​ 517 ​ ​ — ​ 7.00% Notes due June 2028 ​ ​ 261 ​ ​ 261 ​ ​ ​ 264 ​ ​ 264 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ 300 ​ ​ 300 ​ ​ ​ 625 ​ ​ 440 ​ 8.75% Senior Secured Notes due February 2030 ​ ​ 1,175 ​ ​ — ​ ​ ​ 1,151 ​ ​ — ​ 7.50% Notes due April 2031 ​ ​ 396 ​ ​ 396 ​ ​ ​ 395 ​ ​ 394 ​ 6.80% Senior Notes due March 2038 ​ ​ 610 ​ ​ 610 ​ ​ ​ 605 ​ ​ 605 ​ 7.35% Senior Notes due December 2041 ​ ​ 177 ​ ​ 177 ​ ​ ​ 176 ​ ​ 176 ​ Total debt ​ ​ 6,945 ​ ​ 6,963 ​ ​ ​ 7,447 ​ ​ 7,347 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less debt due within one year ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 0.50% Exchangeable Senior Bonds due January 2023 ​ ​ — ​ ​ 49 ​ ​ ​ — ​ ​ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ ​ — ​ ​ 83 ​ ​ ​ — ​ ​ 81 ​ 7.75% Senior Secured Notes due October 2024 ​ ​ — ​ ​ 60 ​ ​ ​ — ​ ​ 59 ​ 6.25% Senior Secured Notes due December 2024 ​ ​ — ​ ​ 62 ​ ​ ​ — ​ ​ 61 ​ 6.125% Senior Secured Notes due August 2025 ​ ​ — ​ ​ 66 ​ ​ ​ — ​ ​ 64 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ — ​ ​ — ​ ​ ​ 1 ​ ​ 6 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ ​ — ​ ​ — ​ ​ ​ 71 ​ ​ 70 ​ 6.875% Senior Secured Notes due February 2027 ​ ​ 76 ​ ​ 69 ​ ​ ​ 74 ​ ​ 67 ​ 4.50% Shipyard Loans due September 2027 ​ ​ 50 ​ ​ 20 ​ ​ ​ 34 ​ ​ 20 ​ 8.75% Senior Secured Notes due February 2030 ​ ​ 117 ​ ​ — ​ ​ ​ 113 ​ ​ — ​ Total debt due within one year ​ ​ 243 ​ ​ 652 ​ ​ ​ 293 ​ ​ 719 ​ Total long-term debt $ 6,702 ​ $ 6,311 ​ $ 7,154 ​ $ 6,628 ​ ​ Scheduled maturities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Other ​ ​ installments installments Total Twelve months ending June 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ $ 243 ​ $ 71 ​ $ 314 ​ 2025 ​ ​ 370 ​ ​ 72 ​ ​ 442 ​ 2026 ​ ​ 1,655 ​ ​ 73 ​ ​ 1,728 ​ 2027 ​ ​ 2,001 ​ ​ 73 ​ ​ 2,074 ​ 2028 ​ ​ 606 ​ ​ — ​ ​ 606 ​ Thereafter ​ ​ 2,070 ​ ​ — ​ ​ 2,070 ​ Total installments of debt ​ $ 6,945 ​ $ 289 ​ ​ 7,234 ​ Total unamortized debt-related balances, net ​ ​ ​ ​ ​ ​ ​ ​ (261) ​ Bifurcated compound exchange feature, at estimated fair value ​ ​ ​ ​ ​ ​ ​ ​ 474 ​ Total carrying amount of debt ​ ​ ​ ​ ​ ​ ​ $ 7,447 ​ ​ Credit agreement Secured Credit Facility Exchangeable bonds Exchange terms ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Implied ​ ​ ​ ​ Exchange exchange Shares ​ rate price issuable 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ 190.4762 ​ ​ 5.25 ​ ​ 56.0 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ 162.1626 ​ ​ 6.17 ​ ​ 4.0 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ 290.6618 ​ ​ 3.44 ​ ​ 87.2 ​ ​ The exchange rates, presented above, are subject to adjustment upon the occurrence of certain events. The 4.00% senior guaranteed exchangeable bonds due December 2025 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 2.50% senior guaranteed exchangeable bonds due January 2027 (the “2.50% Senior Guaranteed Exchangeable Bonds”) may be exchanged by holders into Transocean Ltd. shares at any time prior to the close of business on the second business day immediately preceding the maturity date or redemption date. The 4.625% senior guaranteed exchangeable bonds due September 2029 (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. In April 2023, Perestroika (Cyprus) Ltd., an entity affiliated with one of our directors who beneficially owns approximately 11 percent of our shares, exchanged $213 million aggregate principal amount of the 2.50% Senior Guaranteed Exchangeable Bonds, under the terms of the indenture governing such bonds at the applicable exchange rate presented above. As part of the transaction governing the exchange, we delivered 34.6 million Transocean Ltd. shares and additional immaterial cash consideration to such exchanging holder. The director’s beneficial ownership of our shares resulting from these transactions did not change. Effective interest rates and fair values ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective Fair ​ interest rate value 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ ​ ​ ​ 6.9% ​ ​ 470 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ ​ ​ ​ 0.0% ​ ​ 30 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ ​ ​ ​ 18.3% ​ ​ 703 ​ ​ 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. 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 estimated fair value of the bifurcated compound exchange feature, recorded as a component of the carrying amount of debt, with a corresponding adjustment to interest expense. At June 30, 2023 and December 31, 2022, the carrying amount of the bifurcated compound exchange feature was $474 million and $295 million, respectively. We recognized interest expense for our exchangeable bonds as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ Contractual interest ​ $ 6 ​ $ 3 ​ $ 13 ​ $ 6 ​ Amortization ​ ​ 5 ​ ​ 2 ​ ​ 10 ​ ​ 4 ​ Birfurcated compound exchange feature ​ ​ 46 ​ ​ — ​ ​ 179 ​ ​ — ​ Total ​ $ 57 ​ $ 5 ​ $ 202 ​ $ 10 ​ ​ Debt issuance Senior secured notes Deepwater Titan In January 2023, we issued $1.175 billion aggregate principal amount of 8.75% senior secured notes due February 2030 (the “8.75% Senior Secured Notes”), and we received $1.149 billion aggregate cash proceeds, net of issue costs. The 8.75% Senior Secured Notes are fully and unconditionally guaranteed on an unsecured basis by Transocean Ltd. and on a limited senior secured basis by certain of our wholly owned subsidiaries. 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 Early debt retirement During the six months ended June 30, 2023 and 2022, we redeemed and retired certain notes, for which the aggregate principal amounts, cash payments and recognized loss were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 5.52% Senior Secured Notes due May 2022 ​ $ — ​ $ 18 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ 243 ​ ​ — ​ 5.875% Senior Secured Notes due January 2024 ​ ​ 311 ​ ​ — ​ 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 ​ ​ — ​ Aggregate principal amount of debt retired ​ $ 1,380 ​ $ 18 ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate cash payment ​ $ 1,402 ​ $ 18 ​ Aggregate net loss ​ $ (32) ​ $ — ​ ​ Subsequent event

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2023
Income Taxes
Income Taxes	Note 7—Income Taxes Tax provision and rate Tax positions and returns Brazil tax investigations

Loss Per Share

Loss Per Share	6 Months Ended
	Jun. 30, 2023
Loss per share
Loss per share	Note 8—Loss Per Share The computation of basic and diluted loss per share was as follows (in millions, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ Numerator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to controlling interest ​ $ (165) ​ $ (68) ​ $ (630) ​ $ (243) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares for per share calculation ​ ​ 761 ​ ​ 692 ​ ​ 745 ​ ​ 678 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss per share, basic and diluted ​ $ (0.22) ​ $ (0.10) ​ $ (0.85) ​ $ (0.36) ​ ​ We excluded from the computation certain shares issuable as follows because the effect would have been antidilutive (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ Exchangeable bonds ​ ​ 154.7 ​ ​ 108.1 ​ ​ 168.9 ​ ​ 108.1 ​ Share-based awards ​ ​ 21.7 ​ ​ 14.0 ​ ​ 20.3 ​ ​ 15.0 ​ Warrants ​ ​ 8.9 ​ ​ — ​ ​ 9.1 ​ ​ — ​ ​

Contingencies

Contingencies	6 Months Ended
	Jun. 30, 2023
Contingencies
Contingencies	Note 9—Contingencies 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 June 30, 2023, the subsidiary was a defendant in approximately 200 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 condensed 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 condensed consolidated statement of financial position, results of operations or cash flows.

Equity

Equity	6 Months Ended
	Jun. 30, 2023
Equity
Equity	Note 10—Equity Share issuance

Financial Instruments

Financial Instruments	6 Months Ended
	Jun. 30, 2023
Financial Instruments
Financial Instruments	Note 11—Financial Instruments Overview ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2023 ​ December 31, 2022 ​ ​ Carrying ​ Fair ​ Carrying ​ Fair ​ amount value amount value Cash and cash equivalents $ 821 ​ $ 821 ​ $ 683 ​ $ 683 ​ Restricted cash and cash equivalents ​ ​ 213 ​ ​ 213 ​ ​ 308 ​ ​ 308 ​ Long-term loans receivable from unconsolidated affiliates ​ ​ 44 ​ ​ 44 ​ ​ 41 ​ ​ 43 ​ Total debt ​ ​ 7,447 ​ ​ 7,105 ​ ​ 7,347 ​ ​ 6,412 ​ ​ Cash and cash equivalents Restricted cash and cash equivalents Long-term loans receivable from unconsolidated affiliates Total debt Note 6—Debt

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2023
Significant Accounting Policies
Presentation	Presentation Form 10-K filed on February 23, 2023
Accounting estimates	Accounting estimates
Fair value measurements	Fair value measurements

Revenues (Tables)

Revenues (Tables)	6 Months Ended
	Jun. 30, 2023
Revenues
Schedule of revenue disaggregation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ Six months ended June 30, ​ ​ 2023 ​ 2022 2023 ​ 2022 ​ Ultra- Harsh ​ ​ Ultra- Harsh ​ Ultra- Harsh ​ ​ Ultra- Harsh ​ ​ deepwater environment ​ ​ deepwater environment ​ deepwater environment ​ ​ deepwater environment ​ ​ floaters floaters Total ​ floaters floaters Total floaters floaters Total ​ floaters floaters Total U.S. $ 365 ​ $ — ​ $ 365 ​ $ 253 ​ $ — ​ $ 253 $ 717 ​ $ — ​ $ 717 ​ $ 521 ​ $ — ​ $ 521 Norway ​ ​ — ​ ​ 142 ​ ​ 142 ​ ​ — ​ ​ 241 ​ ​ 241 ​ ​ — ​ ​ 290 ​ ​ 290 ​ ​ — ​ ​ 434 ​ ​ 434 ​ Other countries (a) ​ ​ 171 ​ ​ 51 ​ ​ 222 ​ ​ 198 ​ ​ — ​ ​ 198 ​ ​ 303 ​ ​ 68 ​ ​ 371 ​ ​ 320 ​ ​ 3 ​ ​ 323 ​ Total contract drilling revenues $ 536 ​ $ 193 ​ $ 729 ​ $ 451 ​ $ 241 ​ $ 692 $ 1,020 ​ $ 358 ​ $ 1,378 ​ $ 841 ​ $ 437 ​ $ 1,278 (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	Contract liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ ​ 2023 2022 Deferred contract revenues, recorded in other current liabilities $ 128 ​ $ 124 ​ Deferred contract revenues, recorded in other long-term liabilities ​ ​ 227 ​ ​ 204 ​ Total contract liabilities $ 355 ​ $ 328 ​ Significant changes in contract liabilities were as follows (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ June 30, ​ ​ 2023 2022 Total contract liabilities, beginning of period ​ $ 328 ​ $ 348 ​ Decrease due to recognition of revenues for goods and services ​ ​ (104) ​ ​ (61) ​ Increase due to goods and services transferred over time ​ ​ 131 ​ ​ 30 ​ Total contract liabilities, end of period ​ $ 355 ​ $ 317 ​

Long-Lived Assets (Tables)

Long-Lived Assets (Tables)	6 Months Ended
	Jun. 30, 2023
Long-Lived Assets
Changes in our construction work in progress, including capital expenditures and capitalized interest	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ June 30, ​ ​ 2023 2022 Construction work in progress, beginning of period $ 1,195 ​ $ 1,017 ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital expenditures ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ 114 ​ ​ 193 ​ Other equipment and construction projects ​ ​ 43 ​ ​ 28 ​ Total capital expenditures ​ ​ 157 ​ ​ 221 ​ Non-cash capital additions financed under Shipyard Loan ​ ​ — ​ ​ 300 ​ Changes in accrued capital additions ​ ​ (6) ​ ​ (16) ​ ​ ​ ​ ​ ​ ​ ​ ​ Property and equipment placed into service ​ ​ ​ ​ ​ ​ ​ Newbuild construction program ​ ​ (1,157) ​ ​ — ​ Other equipment and construction projects ​ ​ (20) ​ ​ (26) ​ Construction work in progress, end of period $ 169 ​ $ 1,496 ​

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2023
Debt
Schedule of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal amount ​ ​ Carrying amount ​ ​ June 30, ​ December 31, ​ June 30, ​ December 31, ​ 2023 2022 2023 2022 0.50% Exchangeable Senior Bonds due January 2023 ​ $ — ​ $ 49 ​ ​ $ — ​ $ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ ​ — ​ ​ 352 ​ ​ ​ — ​ ​ 350 ​ 7.75% Senior Secured Notes due October 2024 ​ ​ — ​ ​ 240 ​ ​ ​ — ​ ​ 238 ​ 6.25% Senior Secured Notes due December 2024 ​ ​ — ​ ​ 250 ​ ​ ​ — ​ ​ 248 ​ 6.125% Senior Secured Notes due August 2025 ​ ​ — ​ ​ 336 ​ ​ ​ — ​ ​ 332 ​ 7.25% Senior Notes due November 2025 ​ ​ 354 ​ ​ 354 ​ ​ ​ 351 ​ ​ 351 ​ 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ 294 ​ ​ 294 ​ ​ ​ 274 ​ ​ 271 ​ 7.50% Senior Notes due January 2026 ​ ​ 569 ​ ​ 569 ​ ​ ​ 567 ​ ​ 566 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ 25 ​ ​ 238 ​ ​ ​ 27 ​ ​ 265 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ ​ 687 ​ ​ 687 ​ ​ ​ 973 ​ ​ 1,008 ​ 6.875% Senior Secured Notes due February 2027 ​ ​ 447 ​ ​ 482 ​ ​ ​ 443 ​ ​ 477 ​ 8.00% Senior Notes due February 2027 ​ ​ 612 ​ ​ 612 ​ ​ ​ 609 ​ ​ 608 ​ 7.45% Notes due April 2027 ​ ​ 52 ​ ​ 52 ​ ​ ​ 52 ​ ​ 52 ​ 8.00% Debentures due April 2027 ​ ​ 22 ​ ​ 22 ​ ​ ​ 22 ​ ​ 22 ​ 4.50% Shipyard Loans due September 2027 ​ ​ 439 ​ ​ 439 ​ ​ ​ 396 ​ ​ 389 ​ 8.375% Senior Secured Notes due February 2028 ​ ​ 525 ​ ​ — ​ ​ ​ 517 ​ ​ — ​ 7.00% Notes due June 2028 ​ ​ 261 ​ ​ 261 ​ ​ ​ 264 ​ ​ 264 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ 300 ​ ​ 300 ​ ​ ​ 625 ​ ​ 440 ​ 8.75% Senior Secured Notes due February 2030 ​ ​ 1,175 ​ ​ — ​ ​ ​ 1,151 ​ ​ — ​ 7.50% Notes due April 2031 ​ ​ 396 ​ ​ 396 ​ ​ ​ 395 ​ ​ 394 ​ 6.80% Senior Notes due March 2038 ​ ​ 610 ​ ​ 610 ​ ​ ​ 605 ​ ​ 605 ​ 7.35% Senior Notes due December 2041 ​ ​ 177 ​ ​ 177 ​ ​ ​ 176 ​ ​ 176 ​ Total debt ​ ​ 6,945 ​ ​ 6,963 ​ ​ ​ 7,447 ​ ​ 7,347 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less debt due within one year ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 0.50% Exchangeable Senior Bonds due January 2023 ​ ​ — ​ ​ 49 ​ ​ ​ — ​ ​ 49 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ — ​ ​ 243 ​ ​ ​ — ​ ​ 242 ​ 5.875% Senior Secured Notes due January 2024 ​ ​ — ​ ​ 83 ​ ​ ​ — ​ ​ 81 ​ 7.75% Senior Secured Notes due October 2024 ​ ​ — ​ ​ 60 ​ ​ ​ — ​ ​ 59 ​ 6.25% Senior Secured Notes due December 2024 ​ ​ — ​ ​ 62 ​ ​ ​ — ​ ​ 61 ​ 6.125% Senior Secured Notes due August 2025 ​ ​ — ​ ​ 66 ​ ​ ​ — ​ ​ 64 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ — ​ ​ — ​ ​ ​ 1 ​ ​ 6 ​ 11.50% Senior Guaranteed Notes due January 2027 ​ ​ — ​ ​ — ​ ​ ​ 71 ​ ​ 70 ​ 6.875% Senior Secured Notes due February 2027 ​ ​ 76 ​ ​ 69 ​ ​ ​ 74 ​ ​ 67 ​ 4.50% Shipyard Loans due September 2027 ​ ​ 50 ​ ​ 20 ​ ​ ​ 34 ​ ​ 20 ​ 8.75% Senior Secured Notes due February 2030 ​ ​ 117 ​ ​ — ​ ​ ​ 113 ​ ​ — ​ Total debt due within one year ​ ​ 243 ​ ​ 652 ​ ​ ​ 293 ​ ​ 719 ​ Total long-term debt $ 6,702 ​ $ 6,311 ​ $ 7,154 ​ $ 6,628 ​
Scheduled maturities of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Other ​ ​ installments installments Total Twelve months ending June 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ $ 243 ​ $ 71 ​ $ 314 ​ 2025 ​ ​ 370 ​ ​ 72 ​ ​ 442 ​ 2026 ​ ​ 1,655 ​ ​ 73 ​ ​ 1,728 ​ 2027 ​ ​ 2,001 ​ ​ 73 ​ ​ 2,074 ​ 2028 ​ ​ 606 ​ ​ — ​ ​ 606 ​ Thereafter ​ ​ 2,070 ​ ​ — ​ ​ 2,070 ​ Total installments of debt ​ $ 6,945 ​ $ 289 ​ ​ 7,234 ​ Total unamortized debt-related balances, net ​ ​ ​ ​ ​ ​ ​ ​ (261) ​ Bifurcated compound exchange feature, at estimated fair value ​ ​ ​ ​ ​ ​ ​ ​ 474 ​ Total carrying amount of debt ​ ​ ​ ​ ​ ​ ​ $ 7,447 ​
Schedule of interest expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ Contractual interest ​ $ 6 ​ $ 3 ​ $ 13 ​ $ 6 ​ Amortization ​ ​ 5 ​ ​ 2 ​ ​ 10 ​ ​ 4 ​ Birfurcated compound exchange feature ​ ​ 46 ​ ​ — ​ ​ 179 ​ ​ — ​ Total ​ $ 57 ​ $ 5 ​ $ 202 ​ $ 10 ​
Schedule of debt retirements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 5.52% Senior Secured Notes due May 2022 ​ $ — ​ $ 18 ​ 5.375% Senior Secured Notes due May 2023 ​ ​ 243 ​ ​ — ​ 5.875% Senior Secured Notes due January 2024 ​ ​ 311 ​ ​ — ​ 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 ​ ​ — ​ Aggregate principal amount of debt retired ​ $ 1,380 ​ $ 18 ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate cash payment ​ $ 1,402 ​ $ 18 ​ Aggregate net loss ​ $ (32) ​ $ — ​
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 ​ ​ 56.0 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ 162.1626 ​ ​ 6.17 ​ ​ 4.0 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ 290.6618 ​ ​ 3.44 ​ ​ 87.2 ​ Effective interest rates and fair values ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective Fair ​ interest rate value 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 ​ ​ ​ ​ ​ 6.9% ​ ​ 470 ​ 2.50% Senior Guaranteed Exchangeable Bonds due January 2027 ​ ​ ​ ​ ​ 0.0% ​ ​ 30 ​ 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 ​ ​ ​ ​ ​ 18.3% ​ ​ 703 ​

Loss Per Share (Tables)

Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 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): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ Numerator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to controlling interest ​ $ (165) ​ $ (68) ​ $ (630) ​ $ (243) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for loss per share, basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average shares for per share calculation ​ ​ 761 ​ ​ 692 ​ ​ 745 ​ ​ 678 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss per share, basic and diluted ​ $ (0.22) ​ $ (0.10) ​ $ (0.85) ​ $ (0.36) ​
Schedule of antidilutive securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Six months ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ Exchangeable bonds ​ ​ 154.7 ​ ​ 108.1 ​ ​ 168.9 ​ ​ 108.1 ​ Share-based awards ​ ​ 21.7 ​ ​ 14.0 ​ ​ 20.3 ​ ​ 15.0 ​ Warrants ​ ​ 8.9 ​ ​ — ​ ​ 9.1 ​ ​ — ​

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2023
Financial Instruments
Carrying amounts and fair values of the financial instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2023 ​ December 31, 2022 ​ ​ Carrying ​ Fair ​ Carrying ​ Fair ​ amount value amount value Cash and cash equivalents $ 821 ​ $ 821 ​ $ 683 ​ $ 683 ​ Restricted cash and cash equivalents ​ ​ 213 ​ ​ 213 ​ ​ 308 ​ ​ 308 ​ Long-term loans receivable from unconsolidated affiliates ​ ​ 44 ​ ​ 44 ​ ​ 41 ​ ​ 43 ​ Total debt ​ ​ 7,447 ​ ​ 7,105 ​ ​ 7,347 ​ ​ 6,412 ​

Business (Details)

Business (Details)	Jun. 30, 2023 item
Number of mobile offshore drilling units	37
Ultra-deepwater floaters
Number of mobile offshore drilling units	28
Harsh environment floaters
Number of mobile offshore drilling units	9
Ultra Deepwater drillships
Number of mobile offshore drilling units under construction, noncontrolling interest	1

Unconsolidated Affiliates (Deta

Unconsolidated Affiliates (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended
	Feb. 28, 2023	Jun. 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Investments
Aggregate carrying amount of equity investment		$ 189	$ 189		$ 113
Accounts payable		285	285		281
Equity Method Investee
Investments
Related party receivable		90	90		32
Accounts payable		17	17		2
Global Sea Mineral Resources
Investments
Equity method investment payment	$ 10
Equity investment non-cash contribution	$ 85
Equity in losses			(18)	$ (7)
Aggregate carrying amount of equity investment		95	95
Liquila
Investments
Aggregate carrying amount of equity investment		15	15		$ 15
Orion/Transocean Norge
Investments
Equity method investment payment			19
Orion/Transocean Norge | Reimbursements, Agent Fees and Other Receipts
Investments
Related party transaction		$ 10	50
Orion/Transocean Norge | Services and Equipment
Investments
Related party transaction			$ 5	$ 28

Revenues (Disaggregation) (Deta

Revenues (Disaggregation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue
Contract drilling revenues	$ 729	$ 692	$ 1,378	$ 1,278
U.S.
Revenue
Contract drilling revenues	365	253	717	521
Norway
Revenue
Contract drilling revenues	142	241	290	434
Other Countries
Revenue
Contract drilling revenues	222	198	371	323
Ultra-deepwater floaters
Revenue
Contract drilling revenues	536	451	1,020	841
Ultra-deepwater floaters | U.S.
Revenue
Contract drilling revenues	365	253	717	521
Ultra-deepwater floaters | Other Countries
Revenue
Contract drilling revenues	171	198	303	320
Harsh environment floaters
Revenue
Contract drilling revenues	193	241	358	437
Harsh environment floaters | Norway
Revenue
Contract drilling revenues	142	$ 241	290	434
Harsh environment floaters | Other Countries
Revenue
Contract drilling revenues	$ 51		$ 68	$ 3

Revenues (Contract liabilities)

Revenues (Contract liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Contract balances
Deferred contract revenues, recorded in other current liabilities	$ 128	$ 124
Deferred contract revenues, recorded in other long-term liabilities	227	204
Total contract liabilities	$ 355	$ 328	$ 317	$ 348

Revenues (Changes) (Details)

Revenues (Changes) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Changes to contract liabilities
Total contract liabilities, at beginning of period	$ 328	$ 348
Decrease due to recognition of revenues for goods and services	(104)	(61)
Increase due to goods and services transferred over time	131	30
Total contract liabilities, at end of period	$ 355	$ 317

Revenues (Pre-operating) (Detai

Revenues (Pre-operating) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Revenues
Recognized pre-operating costs	$ 25	$ 24	$ 35	$ 36
Unrecognized pre-operating costs	$ 67		$ 67		$ 26

Long-Lived Assets (Details)

Long-Lived Assets (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Changes in construction work in progress, including capital expenditures and other capital additions, such as capitalized interest
Total capital expenditures	$ 157	$ 221
Non-cash capital additions financed under Shipyard Loan		300
Changes in accrued capital additions	(6)	(16)
Construction in Progress
Changes in construction work in progress, including capital expenditures and other capital additions, such as capitalized interest
Construction work in progress, at beginning of period	1,195	1,017
Construction work in progress, at end of period	169	1,496
New builds
Changes in construction work in progress, including capital expenditures and other capital additions, such as capitalized interest
Total capital expenditures	114	193
Property and equipment placed into service	(1,157)
Other property and equipment
Changes in construction work in progress, including capital expenditures and other capital additions, such as capitalized interest
Total capital expenditures	43	28
Property and equipment placed into service	$ (20)	$ (26)

Long-Lived Assets (Impairment h

Long-Lived Assets (Impairment held for sale) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023
Long-Lived Assets
Aggregate loss on impairment of assets held for sale	$ 53	$ 53
Loss associated with impairment, net of tax (per share)	$ 0.07	$ 0.07
Aggregate loss on impairment of assets held for sale, tax effect	$ 0	$ 0

Long-Lived Assets (Disposal) (D

Long-Lived Assets (Disposal) (Details) $ / shares in Units, kr in Millions, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 NOK (kr)
Dispositions
Gain (loss) on the sale of assets	$ (4)	$ (170)	$ (3)
Proceeds from disposal of assets, net		4	$ 4
Assets sold, not discontinued operations | Rig sales
Dispositions
Gain (loss) on the sale of assets		$ (169)
Gain (loss) on the sale of assets per diluted share | $ / shares		$ (0.23)
Gain (loss) on disposal of assets, tax effect		$ 0
Assets held for sale
Dispositions
Assets held for sale		$ 50		kr 50

Debt (Details)

Debt (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jan. 31, 2023	Dec. 31, 2022
Principal amount
Debt due within one year	$ 243		$ 652
Long-term debt	6,702		6,311
Carrying amount
Total debt	7,447		7,347
Debt due within one year	293		719
Long-term debt	$ 7,154		6,628
0.50% Exchangeable Senior Bonds due January 2023
Principal amount
Total installments of debt			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 of debt			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 of debt			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 of debt			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 of debt			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 of debt			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 of debt	$ 354		354
Carrying amount
Total debt	$ 351		351
Debt instrument interest rate stated percentage	7.25%
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Principal amount
Total installments of debt	$ 294		294
Carrying amount
Total debt	$ 274		271
Debt instrument interest rate stated percentage	4%
7.50% Senior Notes due January 2026
Principal amount
Total installments of debt	$ 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 of debt	$ 25		238
Carrying amount
Total debt	27		265
Debt due within one year	$ 1		6
Debt instrument interest rate stated percentage	2.50%
11.50% Senior Guaranteed Notes due January 2027
Principal amount
Total installments of debt	$ 687		687
Carrying amount
Total debt	973		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 of debt	$ 447		482
Debt due within one year	76		69
Carrying amount
Total debt	443		477
Debt due within one year	$ 74		67
Debt instrument interest rate stated percentage	6.875%
8.00% Senior Notes due February 2027
Principal amount
Total installments of debt	$ 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 of debt	$ 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 of debt	$ 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 of debt	$ 439		439
Debt due within one year	50		20
Carrying amount
Total debt	396		389
Debt due within one year	$ 34		20
Debt instrument interest rate stated percentage	4.50%
8.375% Senior Secured Notes due February 2028
Principal amount
Total installments of debt	$ 525
Carrying amount
Total debt	$ 517
Debt instrument interest rate stated percentage	8.375%	8.375%
7.00% Notes due June 2028
Principal amount
Total installments of debt	$ 261		261
Carrying amount
Total debt	$ 264		264
Debt instrument interest rate stated percentage	7%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Principal amount
Total installments of debt	$ 300		300
Carrying amount
Total debt	$ 625		440
Debt instrument interest rate stated percentage	4.625%
8.75% Senior Secured Notes Due February 2030
Principal amount
Total installments of debt	$ 1,175
Debt due within one year	117
Carrying amount
Total debt	1,151
Debt due within one year	$ 113
Debt instrument interest rate stated percentage	8.75%	8.75%
7.50% Notes due April 2031
Principal amount
Total installments of debt	$ 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 of debt	$ 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 of debt	$ 177		177
Carrying amount
Total debt	$ 176		176
Debt instrument interest rate stated percentage	7.35%
Principal installments
Principal amount
Total installments of debt	$ 6,945		$ 6,963

Debt (Maturities) (Details)

Debt (Maturities) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Total Installments
Scheduled maturities of debt
2024	$ 314
2025	442
2026	1,728
2027	2,074
2028	606
Thereafter	2,070
Total installments of debt	7,234
Total unamortized debt-related balances, net	(261)
Bifurcated compound exchange feature, at estimated fair value	474
Total carrying amount of debt	7,447
Principal installments
Scheduled maturities of debt
2024	243
2025	370
2026	1,655
2027	2,001
2028	606
Thereafter	2,070
Total installments of debt	6,945	$ 6,963
Other installments
Scheduled maturities of debt
2024	71
2025	72
2026	73
2027	73
Total installments of debt	$ 289

Debt (Credit Agreements) (Detai

Debt (Credit Agreements) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Debt
Aggregate cash payment to acquire property	$ 157	$ 221
Five-Year Revolving Credit Facility
Debt
Spread on variable rate basis (as a percent)	0.10%
Early maturity trigger, principal due within 91 days	$ 200
Early maturity trigger available cash	250
Permitted commitment increase	$ 250
Commitment fee percentage at period end	0.75%
Credit facility amount outstanding	$ 0
Letters of credit issued and outstanding	8
Credit facility available borrowing capacity	$ 592
Interest rate, as adjusted (as a percent)	3.25%
Five-Year Revolving Credit Facility | June 2023
Debt
Borrowing capacity, maximum	$ 600
4.50% Shipyard Loan due June 2027
Debt
Aggregate principal amount outstanding	$ 439		$ 439
Debt instrument interest rate stated percentage	4.50%

Debt (Exchange and Issue) (Deta

Debt (Exchange and Issue) (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2023 USD ($) shares	Jun. 30, 2023 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Debt
Restricted cash and cash equivalents		$ 213		$ 213		$ 308
Fair value adjustment to bifurcated compound exchange feature				179
Interest expense		$ 168	$ 100	417	$ 202
Aggregate cash payment				1,402	$ 18
Proceeds from issuance of debt				$ 1,665
Transocean Inc | Perestroika AS
Debt
Ownership interest held by minority interest (as a percent)	11%
0.50% Exchangeable Senior Bonds due January 2023
Debt
Debt instrument interest rate stated percentage		0.50%		0.50%
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Debt
Debt instrument interest rate stated percentage		2.50%		2.50%
Debt conversion ratio				0.1621626
Debt conversion (in dollars per share) | $ / shares		$ 6.17		$ 6.17
Shares issuable (in shares)				4
Effective interest rate (as a percent)		0%		0%
Shares issued upon conversion (in shares) | shares	34.6
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%		4%
Debt conversion ratio				0.1904762
Debt conversion (in dollars per share) | $ / shares		$ 5.25		$ 5.25
Shares issuable (in shares)				56
Effective interest rate (as a percent)		6.90%		6.90%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Debt
Debt instrument interest rate stated percentage		4.625%		4.625%
Debt conversion ratio				0.2906618
Debt conversion (in dollars per share) | $ / shares		$ 3.44		$ 3.44
Shares issuable (in shares)				87.2
Effective interest rate (as a percent)		18.30%		18.30%
Bifurcated compound exchange feature, at estimated fair value		$ 474		$ 474		$ 295
11.50% Senior Guaranteed Notes due January 2027
Debt
Debt instrument interest rate stated percentage		11.50%		11.50%
8.00% Senior Notes due February 2027
Debt
Debt instrument interest rate stated percentage		8%		8%
7.25% Senior Notes due November 2025
Debt
Debt instrument interest rate stated percentage		7.25%		7.25%

Debt (Interest Expense) (Detail

Debt (Interest Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Interest Expense
Bifurcated compound exchange feature			$ 179
Total interest expense	$ 168	$ 100	$ 417	$ 202
Exchangeable bonds
Interest Expense
Contractual interest	6	3
Amortization	5	2
Bifurcated compound exchange feature	46
Total interest expense	$ 57	$ 5

Debt (Debt issuance) (Details)

Debt (Debt issuance) (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Jan. 31, 2023	Jun. 30, 2023	Jun. 30, 2022
Debt
Proceeds from issuance of debt		$ 1,665
Aggregate cash payment		$ 1,402	$ 18
8.375% Senior Secured Notes due February 2028
Debt
Debt instrument face value	$ 525
Debt instrument interest rate stated percentage	8.375%	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%	8.75%
Proceeds from issuance of debt	$ 1,149
Redemption price of debt instrument (as a percent)	100%

Debt (Settled) (Details)

Debt (Settled) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Debt
Aggregate principal amount of debt retired	$ 1,380	$ 18
Aggregate cash payment	1,402	18
Aggregate net loss	(32)
Repayments of debt	$ 1,568	257
5.52% Senior Secured Notes due May 2022
Debt
Aggregate principal amount of debt retired		$ 18
Debt instrument interest rate stated percentage	5.52%
5.375% Senior Secured Notes due May 2023
Debt
Aggregate principal amount of debt retired	$ 243
Debt instrument interest rate stated percentage	5.375%
5.875% Senior Secured Notes due January 2024
Debt
Aggregate principal amount of debt retired	$ 311
Debt instrument interest rate stated percentage	5.875%
7.75% Senior Secured Notes due October 2024
Debt
Aggregate principal amount of debt retired	$ 240
Debt instrument interest rate stated percentage	7.75%
6.25% Senior Secured Notes due December 2024
Debt
Aggregate principal amount of debt retired	$ 250
Debt instrument interest rate stated percentage	6.25%
6.125% Senior Secured Notes due August 2025
Debt
Aggregate principal amount of debt retired	$ 336
Debt instrument interest rate stated percentage	6.125%

Debt (Subsequent event) (Detail

Debt (Subsequent event) (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Jul. 31, 2023	Jun. 30, 2023	Jun. 30, 2022
Debt
Aggregate principal amount to redeem		$ 1,380	$ 18
Aggregate cash payment		$ 1,402	$ 18
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Debt
Debt instrument interest rate stated percentage		2.50%
2.50% Senior Guaranteed Exchangeable Bonds due January 2027 | Subsequent Events
Debt
Aggregate principal amount to redeem	$ 25
2.50% Senior Guaranteed Exchangeable Bonds due January 2027 | Forecast
Debt
Aggregate cash payment	$ 25

Income Taxes (Provision) (Detai

Income Taxes (Provision) (Details) R$ in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2023 BRL (R$)	Jun. 30, 2022 USD ($)
Effective tax rate			(5.90%)	(5.90%)	(13.70%)
Income tax expense (benefit)	$ (16)	$ 3	$ 35		$ 29
Various discrete tax items expense (benefit)			$ (12)		$ (8)
Annual effective tax rate excluding discrete items (as a percent)			(14.00%)	(14.00%)	(17.50%)
Brazil | Corporate income tax
Net adjustments of additional taxes, including interest and penalties			$ 143	R$ 683
Brazil | Indirect tax
Net adjustments of additional taxes, including interest and penalties			$ 15	R$ 74

Loss Per Share (Details)

Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings per share
Net Income (Loss)	$ (165)	$ (68)	$ (630)	$ (243)
Weighted-average shares for per share calculation, basic (in shares)	761	692	745	678
Weighted-average shares for per share calculation, diluted (in shares)	761	692	745	678
Loss per share, basic (in dollars per share)	$ (0.22)	$ (0.10)	$ (0.85)	$ (0.36)
Loss per share, diluted (in dollars per share)	$ (0.22)	$ (0.10)	$ (0.85)	$ (0.36)
Exchangeable bonds
Earnings per share
Securities excluded from earnings per share calculation (in shares)	154.7	108.1	168.9	108.1
Share-based awards
Earnings per share
Securities excluded from earnings per share calculation (in shares)	21.7	14	20.3	15
Warrant
Earnings per share
Securities excluded from earnings per share calculation (in shares)	8.9		9.1

Contingencies (Legal proceeding

Contingencies (Legal proceedings) (Details) - Asbestos litigation	Jun. 30, 2023 plaintiff lawsuit
Contingencies
Number of claims | lawsuit	200
Louisiana
Contingencies
Number of claims	7
Illinois and Missouri
Contingencies
Number of claims	10

Equity (Share Issuance) (Detail

Equity (Share Issuance) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022
Equity
Proceeds from issuance of shares, net of issue costs		$ 206
ATM Program
Equity
Proceeds from issuance of shares, net of issue costs	$ 103	$ 206
Issuance of shares (in shares)	24.6	44.8

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Financial instruments
Carrying amount of debt	$ 7,447	$ 7,347
Carrying amount
Financial instruments
Cash and cash equivalents	821	683
Restricted cash and cash equivalents	213	308
Long-term loans receivable from unconsolidated affiliates	44	41
Carrying amount of debt	7,447	7,347
Fair value
Financial instruments
Cash and cash equivalents	821	683
Restricted cash and cash equivalents	213	308
Long-term loans receivable from unconsolidated affiliates	44	43
Carrying amount of debt	$ 7,105	$ 6,412

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ (165)	$ (68)	$ (630)	$ (243)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		During the three months ended June 30, 2023, no director or officer of Transocean adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false