DT Midstream (DTM) 10-Q 1 Nov 23 2023 Q3 Quarterly report Financial data

Cover

Cover	9 Months Ended
	Sep. 30, 2023 shares
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-40392
Entity Registrant Name	DT Midstream, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	38-2663964
Entity Address, Address Line One	500 Woodward Ave., Suite 2900
Entity Address, City or Town	Detroit
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	48226-1279
City Area Code	313
Local Phone Number	402-8532
Title of 12(b) Security	Common stock, par value $0.01
Trading Symbol	DTM
Security Exchange Name	NYSE
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	96,971,021
Entity Central Index Key	0001842022
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues
Operating revenues	$ 234	$ 235	$ 678	$ 677
Operating Expenses
Operation and maintenance	58	65	176	189
Depreciation and amortization	46	42	133	126
Taxes other than income	7	7	22	23
Asset (gains) losses and impairments, net	(1)	0	(4)	(23)
Operating Income	124	121	351	362
Other (Income) and Deductions
Interest expense	38	35	111	99
Interest income	0	(1)	(1)	(2)
Earnings from equity method investees	(41)	(36)	(132)	(107)
Loss from financing activities	0	0	0	13
Other (income) and expense	0	0	(1)	0
Income Before Income Taxes	127	123	374	359
Income Tax Expense	33	7	102	65
Net Income	94	116	272	294
Less: Net Income Attributable to Noncontrolling Interests	3	3	9	9
Net Income Attributable to DT Midstream	$ 91	$ 113	$ 263	$ 285
Basic Earnings per Common Share
Net Income Attributable to DT Midstream (in dollars per share)	$ 0.94	$ 1.17	$ 2.72	$ 2.94
Diluted Earnings per Common Share
Net Income Attributable to DT Midstream (in dollars per share)	$ 0.94	$ 1.16	$ 2.70	$ 2.94
Weighted Average Common Shares Outstanding
Basic (in shares)	97	96.7	96.9	96.7
Diluted (in shares)	97.5	97	97.4	97

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net Income	$ 94	$ 116	$ 272	$ 294
Foreign currency translation and unrealized gain on derivatives, net of tax	0	1	1	2
Other comprehensive income	0	1	1	2
Comprehensive income	94	117	273	296
Less: Comprehensive income attributable to noncontrolling interests	3	3	9	9
Comprehensive Income Attributable to DT Midstream	$ 91	$ 114	$ 264	$ 287

Consolidated Statements of Fina

Consolidated Statements of Financial Position - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Current Assets
Cash and cash equivalents	$ 30	$ 61
Accounts receivable (net of $— allowance for expected credit loss for each period end)	146	161
Deferred property taxes	6	22
Prepaid expenses and other	18	18
Total Current Assets	200	262
Investments
Investments in equity method investees	1,782	2,200
Property
Property, plant, and equipment	5,162	4,534
Accumulated depreciation	(814)	(728)
Net Property, plant, and equipment	4,348	3,806
Other Assets
Goodwill	473	473
Long-term notes receivable — related party	4	4
Operating lease right-of-use assets	42	31
Intangible assets, net	1,982	2,025
Other	31	32
Total Other Assets	2,532	2,565
Total Assets	8,862	8,833
Current Liabilities
Accounts payable	124	119
Short-term borrowings	125	330
Operating lease liabilities	15	16
Dividends payable	67	62
Interest payable	39	10
Property taxes payable	17	29
Accrued compensation	13	20
Other	24	28
Total Current Liabilities	424	614
Long-Term Debt	3,064	3,059
Other Liabilities
Deferred income taxes	1,014	923
Operating lease liabilities	30	19
Other	109	64
Total Other Liabilities	1,153	1,006
Total Liabilities	4,641	4,679
Commitments and Contingencies (Note 9)
Stockholders' Equity
Preferred stock ($0.01 par value, 50,000,000 shares authorized, and no shares issued or outstanding as of September 30, 2023 and December 31, 2022)	0	0
Common stock ($0.01 par value, 550,000,000 shares authorized, and 96,971,021 and 96,754,549 shares issued and outstanding as of September 30, 2023 and December 31, 2022, respectively)	1	1
Additional paid-in capital	3,479	3,469
Retained earnings	608	547
Accumulated other comprehensive income (loss)	(9)	(10)
Total DT Midstream Equity	4,079	4,007
Noncontrolling interests	142	147
Total Equity	4,221	4,154
Total Liabilities and Equity	$ 8,862	$ 8,833

Consolidated Statements of Fi_2

Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Current Assets
Allowance for expected credit loss	$ 0	$ 0
Stockholders' Equity
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	550,000,000	550,000,000
Common stock, shares issued (in shares)	96,971,021	96,754,549
Common stock, shares outstanding (in shares)	96,971,021	96,754,549

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating Activities
Net Income	$ 272	$ 294
Adjustments to reconcile Net Income to Net cash and cash equivalents from operating activities:
Depreciation and amortization	133	126
Stock-based compensation	15	13
Amortization of operating lease right-of-use assets	14	14
Deferred income taxes	91	51
Earnings from equity method investees	(132)	(107)
Dividends from equity method investees	152	125
Asset (gains) losses and impairments, net	0	(17)
Loss from financing activities	0	13
Changes in assets and liabilities:
Accounts receivable, net	15	19
Accounts payable	(4)	(2)
Interest payable	29	35
Other current and noncurrent assets and liabilities	29	10
Net cash and cash equivalents from operating activities	614	574
Investing Activities
Plant and equipment expenditures	(622)	(173)
Proceeds from sale of notes receivable	0	22
Distributions from equity method investees	405	3
Contributions to equity method investees	(6)	(4)
Notes receivable — third party	0	2
Net cash and cash equivalents from (used for) investing activities	(223)	(150)
Financing Activities
Issuance of long-term debt, net of discount and issuance costs	0	591
Repayment of long-term debt	0	(596)
Borrowings under the Revolving Credit Facility	390	0
Repayment of borrowings under the Revolving Credit Facility	(595)	0
Repurchase of common stock	0	(3)
Distributions to noncontrolling interests	(14)	(11)
Dividends paid on common stock	(196)	(182)
Other financing activities	(7)	0
Net cash and cash equivalents from (used for) financing activities	(422)	(201)
Net Increase (Decrease) in Cash and Cash Equivalents	(31)	223
Cash and Cash Equivalents at Beginning of Period	61	132
Cash and Cash Equivalents at End of Period	30	355
Supplemental disclosure of cash information
Interest, net of interest capitalized	76	59
Income taxes	21	9
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable and other accruals	$ 109	$ 60

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning Balance (in shares) at Dec. 31, 2021		96,734,000
Beginning Balance at Dec. 31, 2021	$ 4,021	$ 1	$ 3,450	$ 431	$ (10)	$ 149
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	84			81		3
Dividends declared on common stock	(62)			(62)
Distributions to noncontrolling interests	(4)					(4)
Stock-based compensation (in shares)		57,000
Stock-based compensation	2		3	(1)
Repurchase of common stock (in shares)		(57,000)
Repurchase of common stock	(3)			(3)
Ending Balance (in shares) at Mar. 31, 2022		96,734,000
Ending Balance at Mar. 31, 2022	4,038	$ 1	3,453	446	(10)	148
Beginning Balance (in shares) at Dec. 31, 2021		96,734,000
Beginning Balance at Dec. 31, 2021	4,021	$ 1	3,450	431	(10)	149
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	294
Other comprehensive income, net of tax	2
Ending Balance (in shares) at Sep. 30, 2022		96,751,000
Ending Balance at Sep. 30, 2022	4,125	$ 1	3,462	523	(8)	147
Beginning Balance (in shares) at Mar. 31, 2022		96,734,000
Beginning Balance at Mar. 31, 2022	4,038	$ 1	3,453	446	(10)	148
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	94			91		3
Dividends declared on common stock	(62)			(62)
Distributions to noncontrolling interests	(3)					(3)
Stock-based compensation	4		5	(1)
Taxes and other adjustments	(1)			(1)
Other comprehensive income, net of tax	1				1
Ending Balance (in shares) at Jun. 30, 2022		96,734,000
Ending Balance at Jun. 30, 2022	4,071	$ 1	3,458	473	(9)	148
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	116			113		3
Dividends declared on common stock	(62)			(62)
Distributions to noncontrolling interests	(4)					(4)
Stock-based compensation (in shares)		17,000
Stock-based compensation	4		4
Taxes and other adjustments	(1)			(1)
Other comprehensive income, net of tax	1				1
Ending Balance (in shares) at Sep. 30, 2022		96,751,000
Ending Balance at Sep. 30, 2022	4,125	$ 1	3,462	523	(8)	147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared on common stock	$ (62)
Ending Balance (in shares) at Dec. 31, 2022	96,754,549	96,755,000
Ending Balance at Dec. 31, 2022	$ 4,154	$ 1	3,469	547	(10)	147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	84			81		3
Dividends declared on common stock	(67)			(67)
Distributions to noncontrolling interests	(8)					(8)
Stock-based compensation (in shares)		135,000
Stock-based compensation	1		1
Other comprehensive income, net of tax	1				1
Ending Balance (in shares) at Mar. 31, 2023		96,890,000
Ending Balance at Mar. 31, 2023	$ 4,165	$ 1	3,470	561	(9)	142
Beginning Balance (in shares) at Dec. 31, 2022	96,754,549	96,755,000
Beginning Balance at Dec. 31, 2022	$ 4,154	$ 1	3,469	547	(10)	147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	272
Other comprehensive income, net of tax	$ 1
Ending Balance (in shares) at Sep. 30, 2023	96,971,021	96,971,000
Ending Balance at Sep. 30, 2023	$ 4,221	$ 1	3,479	608	(9)	142
Beginning Balance (in shares) at Mar. 31, 2023		96,890,000
Beginning Balance at Mar. 31, 2023	4,165	$ 1	3,470	561	(9)	142
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	94			91		3
Dividends declared on common stock	(67)			(67)
Distributions to noncontrolling interests	(2)					(2)
Stock-based compensation (in shares)		12,000
Stock-based compensation	5		6	(1)
Ending Balance (in shares) at Jun. 30, 2023		96,902,000
Ending Balance at Jun. 30, 2023	4,195	$ 1	3,476	584	(9)	143
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	94			91		3
Dividends declared on common stock	(67)			(67)
Distributions to noncontrolling interests	(4)					(4)
Stock-based compensation (in shares)		69,000
Stock-based compensation	3		3
Other comprehensive income, net of tax	$ 0
Ending Balance (in shares) at Sep. 30, 2023	96,971,021	96,971,000
Ending Balance at Sep. 30, 2023	$ 4,221	$ 1	$ 3,479	$ 608	$ (9)	$ 142

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 0.69	$ 0.69	$ 0.69	$ 0.64	$ 0.64	$ 0.64	$ 0.64

Description of the Business and

Description of the Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business and Basis of Presentation	DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION Description of the Business DT Midstream is an owner, operator, and developer of an integrated portfolio of natural gas midstream assets. The Company provides multiple, integrated natural gas services to customers through two segments: (i) Pipeline, which includes interstate pipelines, intrastate pipelines, storage systems, lateral pipelines including related treatment plants and compression and surface facilities, and (ii) Gathering, which includes gathering systems, related treatment plants, and compression and surface facilities. DT Midstream's Pipeline segment also includes joint venture interests in equity method investees which own and operate interstate pipelines that connect to DT Midstream’s wholly owned assets. DT Midstream’s core assets strategically connect key demand centers in the Midwestern U.S., Eastern Canada and Northeastern U.S. regions to the premium production areas of the Marcellus/Utica natural gas formation in the Appalachian Basin, and connect key demand centers and LNG export terminals in the Gulf Coast region to premium production areas of the Haynesville natural gas formation. Basis of Presentation The DT Midstream Consolidated Financial Statements and Notes to Consolidated Financial Statements are prepared under GAAP. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from DT Midstream’s estimates. DT Midstream believes the assumptions underlying these financial statements are reasonable. Certain prior-period amounts have been reclassified to conform to current-year presentation. In DT Midstream's opinion, the accompanying unaudited Consolidated Financial Statements include all adjustments, consisting of normal recurring adjustments, necessary to present a fair statement of our financial position as of September 30, 2023, results of operations for the three and nine months ended September 30, 2023 and 2022, statement of changes in stockholders' equity for the three and nine months ended September 30, 2023 and 2022, and cash flows for the nine months ended September 30, 2023 and 2022. The balance sheet as of December 31, 2022 was derived from audited annual financial statements but does not include all disclosures required by GAAP. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the year ending December 31, 2023. The Consolidated Financial Statements should be read in conjunction with DT Midstream's Consolidated Financial Statements and Notes to Consolidated Financial Statements included in DT Midstream's 2022 Annual Report on Form 10-K. Principles of Consolidation DT Midstream consolidates all majority-owned subsidiaries and investments in entities in which we have a controlling influence. Non-controlled investments are accounted for using the equity method of accounting when DT Midstream is able to significantly influence the operating policies of the investee. When DT Midstream does not influence the operating policies of an investee, the equity investment is measured at fair value, if readily determinable, or if not readily determinable, at cost less impairment, if applicable. DT Midstream eliminates all intercompany balances and transactions. DT Midstream evaluates whether an entity is a VIE whenever reconsideration events occur. DT Midstream consolidates VIEs for which we are the primary beneficiary. If DT Midstream is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, DT Midstream considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. DT Midstream performs ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. DT Midstream owns an 85% interest in the Stonewall Gas Gathering VIE and is the primary beneficiary, therefore Stonewall Gas Gathering is consolidated. DT Midstream owns a 50% interest in the South Romeo VIE and is the primary beneficiary, therefore South Romeo is consolidated. The following table summarizes the major line items in the Consolidated Statements of Financial Position for consolidated VIEs as of September 30, 2023 and December 31, 2022. All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. The assets and liabilities of consolidated VIEs that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIEs' obligations have been excluded from the table below. Amounts for consolidated VIEs are as follows: September 30, December 31, 2023 2022 (millions) ASSETS (a) Cash $ 11 $ 27 Accounts receivable 8 9 Other current assets 1 3 Intangible assets, net 487 498 Property, plant and equipment, net 394 403 Goodwill 25 25 $ 926 $ 965 LIABILITIES (a) Accounts payable and other current liabilities $ 2 $ 4 Other noncurrent liabilities 4 4 $ 6 $ 8 _____________________________________ (a) Amounts shown are 100% of the consolidated VIEs' assets and liabilities. Related Parties Transactions between DT Midstream and our equity method investees have been presented as related party transactions in the accompanying Consolidated Financial Statements. Equity Method Investments Non-controlled investments are accounted for using the equity method of accounting when DT Midstream is able to significantly influence the operating policies of the investee. Under the equity method of accounting, investments are recorded at historical cost as an asset and adjusted for capital contributions, dividends and distributions received, and the Company's share of the investee's earnings or losses, which are recorded as earnings from equity method investees on the Consolidated Statements of Operations. DT Midstream's equity method investments are periodically evaluated for certain factors that may be indicative of other-than-temporary impairment. As of September 30, 2023 and December 31, 2022, DT Midstream’s carrying amounts of investments in equity method investees exceeded our share of the underlying equity in the net assets of the investees by $356 million and $368 million, respectively. The difference will be amortized over the life of the underlying assets. As of September 30, 2023 and December 31, 2022, DT Midstream's consolidated retained earnings balance includes undistributed earnings from equity method investments of zero and $43 million, respectively. DT Midstream uses the cumulative earnings approach to classify proceeds received from equity method investees as dividends or distributions on the Consolidated Statements of Cash Flows. Equity method investees are described below: Investments As of % Owned As of September 30, December 31, September 30, December 31, Equity Method Investee 2023 2022 2023 2022 (millions) NEXUS $ 916 $ 1,313 50% 50% Vector 137 135 40% 40% Millennium 729 752 52.5% 52.5% Total investments in equity method investees $ 1,782 $ 2,200 In May 2023, NEXUS closed on the sale of $750 million of senior unsecured notes with a weighted-average coupon rate of 5.52%. DT Midstream received a distribution from NEXUS of $371 million, net of fees and expenses, which reduced our investment balance. DT Midstream used the proceeds from the distribution to repay borrowings outstanding under our Revolving Credit Facility. In October 2022, DT Midstream closed on the $552 million purchase of an additional 26.25% ownership interest in Millennium from National Grid. The transaction was financed with cash on hand and available capacity under the Company's Revolving Credit Facility. The purchase constituted National Grid's full ownership interests in Millennium and brought DT Midstream's total ownership interest in Millennium to 52.5%. DT Midstream accounts for our ownership interest in Millennium under the equity method of accounting. Millennium is not a VIE and DT Midstream does not have a controlling interest due to shared control with our partner over all of Millennium's significant business activities. DT Midstream’s carrying amount of our Millennium investment exceeded our share of the underlying equity in the net assets of Millennium by $343 million on the acquisition date. The following table presents summarized financial information of DT Midstream's non-consolidated equity method investees. The amounts included below represent 100% of the results of continuing operations of such entities, including the portion owned by other parties. Summarized income statement data is as follows: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Operating revenues $ 201 $ 194 $ 611 $ 583 Operating expenses 94 94 282 282 Net Income $ 91 $ 93 $ 292 $ 277

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Cash and Cash Equivalents Cash and cash equivalents include cash in banks and highly liquid money market investments with remaining maturities of three months or less, when purchased. Cash equivalents are stated at cost, which approximates fair value. Financing Receivables Financing receivables are primarily composed of trade accounts receivable and notes receivable, which are stated at net realizable value. DT Midstream regularly monitors the credit quality of our financing receivables by reviewing counterparty credit quality indicators and monitoring for triggering events, such as a credit rating downgrade or bankruptcy. DT Midstream has three internal grades of credit quality, with internal grade 1 as the lowest risk and internal grade 3 as the highest risk. The related credit quality indicators and risk ratings utilized to develop the internal grades have been updated through September 30, 2023. As of September 30, 2023, the Notes receivable — related party of $4 million, which originated prior to 2021, was classified as internal grade 1. There are no notes receivable on nonaccrual status and no past due financing receivables as of September 30, 2023. For trade accounts receivable, the customer allowance for expected credit loss is calculated based on specific review of future collections based on receivable balances generally in excess of 30 days. Existing and future economic conditions, historical loss rates, customer trends and other relevant factors that may affect our ability to collect are also considered. Receivables are written off on a specific identification basis and determined based on the particular circumstances of the associated receivable. Uncollectible expense (recovery) was zero for the three and nine months ended September 30, 2023 and 2022. Our collections on accounts receivable from customers are current, and no material rate of historical loss was noted, which resulted in no allowance for expected credit loss as of September 30, 2023 or December 31, 2022. Any balance would be shown as a deduction from the respective financing receivable's balance in the Consolidated Statements of Financial Position. Operation and Maintenance Operation and maintenance is primarily comprised of costs for labor and employee benefits, outside services, materials, compression, purchased natural gas, operating lease costs, office costs, and other operating and maintenance costs.

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	GOODWILL DT Midstream has goodwill that resulted from business combinations. The carrying value of goodwill is evaluated for impairment on an annual basis or whenever events or circumstances indicate that the value of goodwill may be impaired. We performed our prior year annual impairment test as of October 1, 2022 and determined that the estimated fair value of each reporting unit exceeded its carrying value, and no impairment existed. No additions, impairments or other changes occurred during the three and nine months ended September 30, 2023. The following is the summary of the carrying value of goodwill: September 30, December 31, 2023 2022 (millions) Pipeline $ 53 $ 53 Gathering 420 420 Total goodwill $ 473 $ 473 While we believe the estimates and assumptions in the fair value are reasonable, the actual results may differ from projections. To the extent projected results or cash flows are revised downward, the reporting unit may be required to write down all or a portion of its goodwill, which would adversely impact our earnings. If current expectations of future long-term growth are not met or market factors outside of our control change, such as U.S. Treasury Rates or declines in midstream industry transaction multiples, this may lead to a goodwill impairment in the future.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE Disaggregation of Revenue The following is a summary of revenues disaggregated by segment: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Pipeline (a) $ 96 $ 87 $ 271 $ 247 Gathering 138 148 407 430 Total operating revenues $ 234 $ 235 $ 678 $ 677 __________________________________ (a) Includes revenues outside the scope of Topic 606 primarily related to contracts accounted for as leases of $2 million and $3 million for the three months ended September 30, 2023 and 2022, respectively, and $5 million and $7 million for the nine months ended September 30, 2023 and 2022, respectively. Nature of Services DT Midstream primarily provides two types of revenue services: firm service and interruptible service. Firm service revenue contracts provide for fixed revenue commitments regardless of actual volumes of natural gas that flow, which leads to more stable operating performance, revenues and cash flows and limits our exposure to natural gas price fluctuations. Firm service revenue contracts are typically long-term and structured using fixed demand charges or MVCs with fixed deficiency fee rates. Contracts structured using fixed demand charges contain a performance obligation of a stand-ready series of distinct services that are substantially the same with the same pattern of transfer to the customer, therefore revenue is recognized ratably over time. Contracts structured using MVCs with fixed deficiency fee rates require customers to transport or store a minimum volume of natural gas over a specified time period. If a customer fails to meet its MVCs for the specified time period, the contract consideration includes a fixed rate for the actual volumes transported, gathered or stored, and a deficiency fee for the shortfall between the MVCs and the actual volumes transported, gathered or stored. If a customer exceeds its MVC for the specified time period, the contract consideration is based on fixed rates for the actual volumes transported, gathered or stored. The contract consideration is allocated to each distinct monthly performance obligation, consistent with the allocation objective and based upon the level of effort required to satisfy the service obligation. Revenues are generally recognized over time based on the output measure of natural gas volumes transported, gathered or stored, with the recognition of the deficiency fee revenue in the period when it is known the customer cannot make up the deficient volumes in the specified time period. Interruptible service revenue contracts typically contain fixed rates, with total consideration dependent on actual natural gas volumes that flow. Interruptible service revenues are recognized over time based on the output measure of natural gas volumes transported, gathered or stored. Certain of our gathering contracts allow for the recovery of production-related operating expenses, which are recorded as revenue and operating expense. Contract Liabilities The following is a summary of contract liability activity: 2023 (millions) Balance as of January 1 $ 32 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 62 Revenue recognized that was included in the balance at the beginning of the period (3) Balance as of September 30 $ 91 The contract liabilities at DT Midstream generally represent amounts paid by or receivable from customers for which the associated performance obligation has not yet been satisfied. Contract liabilities associated with these services are recognized upon delivery of the service to the customer. The following table presents contract liability amounts as of September 30, 2023 that are expected to be recognized as revenue in future periods: (millions) Remainder of 2023 $ 3 2024 13 2025 13 2026 13 2027 13 2028 and thereafter 36 Total $ 91 Transaction Price Allocated to the Remaining Performance Obligations In accordance with optional exemptions available under Topic 606, DT Midstream does not disclose the value of unsatisfied performance obligations for (1) contracts with an original expected length of one year or less, (2) with the exception of fixed consideration, contracts for which the amount of revenue recognized depends upon DT Midstream's invoices for actual volumes transported, gathered or stored, and (3) contracts for which variable consideration relates entirely to an unsatisfied performance obligation. Such contracts consist of various types of performance obligations, including providing midstream services. Contracts with variable volumes and/or variable pricing, including those with pricing provisions tied to a consumer price or other index, have also been excluded as the related contract consideration is variable at the contract inception. Contract lengths vary from cancellable to multi-year. The following table presents revenue amounts related to fixed consideration associated with unsatisfied performance obligations as of September 30, 2023 that are expected to be recognized as revenue in future periods: (millions) Remainder of 2023 $ 27 2024 129 2025 133 2026 103 2027 71 2028 and thereafter 247 Total $ 710 Costs to Obtain or Fulfill a Contract DT Midstream recognizes an asset from the costs incurred to obtain a revenue contract only if it expects to recover those costs. In addition, the costs to fulfill a revenue contract are capitalized if the costs are specifically identifiable to a revenue contract, would result in enhancing resources that will be used in satisfying performance obligations in the future, and are expected to be recovered. These capitalized costs are amortized on a systematic basis consistent with the pattern of transfer of the services to which such costs relate.

Earnings Per Share and Dividend

Earnings Per Share and Dividends	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share and Dividends	EARNINGS PER SHARE AND DIVIDENDS Basic earnings per share is calculated by dividing Net Income attributable to DT Midstream by the weighted average number of common shares outstanding during the period. Diluted earnings per share reflect the dilution that would occur if any potentially dilutive instruments were exercised or converted into common shares. Restricted stock units and performance shares, including dividend equivalents on those grants, are potentially dilutive and, if dilutive, are included in the determination of weighted average shares outstanding. Restricted stock units and performance shares do not receive cash dividends, as such, these awards are not considered participating securities. The following is a reconciliation of DT Midstream's basic and diluted earnings per share calculation: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions, except per share amounts) Basic and Diluted Earnings per Common Share Net Income Attributable to DT Midstream $ 91 $ 113 $ 263 $ 285 Average number of common shares outstanding — basic 97.0 96.7 96.9 96.7 Incremental shares attributable to: Average dilutive restricted stock units and performance share awards 0.5 0.3 0.5 0.3 Average number of common shares outstanding — diluted 97.5 97.0 97.4 97.0 Basic Earnings per Common Share $ 0.94 $ 1.17 $ 2.72 $ 2.94 Diluted Earnings per Common Share $ 0.94 $ 1.16 $ 2.70 $ 2.94 DT Midstream declared the following cash dividends: Dividends Declared Dividend Amount Dividend Payment Date (quarter ended) (per-share) (millions) 2022 March 31 $ 0.64 $ 62 April 2022 June 30 $ 0.64 $ 62 July 2022 September 30 $ 0.64 $ 62 October 2022 December 31 $ 0.64 $ 62 January 2023 2023 March 31 $ 0.69 $ 67 April 2023 June 30 $ 0.69 $ 67 July 2023 September 30 $ 0.69 $ 67 October 2023

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Effective Tax Rates DT Midstream records income taxes during the interim period using an estimated annual effective tax rate (ETR) and recognizes specific events discretely as they occur.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable inputs. DT Midstream makes certain assumptions it believes that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. DT Midstream believes it uses valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. DT Midstream classifies fair value balances based on the fair value hierarchy defined as follows: • Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that DT Midstream has the ability to access as of the reporting date. • Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the assets or liabilities or indirectly observable through corroboration with observable market data. • Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints. Fair Value of Financial Instruments The following table presents the carrying amount and fair value of financial instruments: September 30, 2023 December 31, 2022 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (millions) Cash equivalents (a) $ 13 $ — $ 13 $ — $ — $ — $ — $ — Long-term notes receivable — related party 4 — — 4 4 — — 4 Short-term borrowings (a) 125 — 125 — 330 — 330 — Long-term debt (b) $ 3,064 $ — $ 2,693 $ — $ 3,059 $ — $ 2,701 $ — ______________________________________ (a) Short-term borrowings and money market cash equivalents are stated at cost, which approximates fair value. (b) Carrying value represents principal of $3,099 million, net of unamortized debt discounts and issuance costs.

Debt

Debt	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Debt	DEBT Long-Term Debt DT Midstream's long-term debt outstanding included: Maturity September 30, December 31, Title Type Interest Rate Date (d) 2023 2022 (millions) 2029 Notes Senior Notes (a) 4.125% 2029 $ 1,100 $ 1,100 2031 Notes Senior Notes (a) 4.375% 2031 1,000 1,000 2032 Notes Senior Secured Notes (b) 4.300% 2032 600 600 Term Loan Facility Term Loan Facility Variable (c) 2028 399 399 Long-term debt principal 3,099 3,099 Unamortized debt discount (2) (3) Unamortized debt issuance costs (33) (37) Long-term debt $ 3,064 $ 3,059 ______________________________ (a) Interest payable semi-annually in arrears each June 15 and December 15. (b) Interest payable semi-annually in arrears each April 15 and October 15. (c) Variable rate is SOFR plus 2.11% for a one-month interest period as of September 30, 2023. (d) DT Midstream does not have any scheduled debt maturities until 2028. Short-Term Credit Arrangements and Borrowings The following table presents the availability under the Revolving Credit Facility: September 30, 2023 (millions) Total availability Revolving Credit Facility, expiring October 2027 $ 1,000 Amounts outstanding Revolving Credit Facility borrowings 125 Letters of credit 16 141 Net availability $ 859 Borrowings under the Revolving Credit Facility are used for general corporate purposes, acquisitions, and letter of credit issuances to support DT Midstream's operations and liquidity. In April 2023, certain letters of credit totaling $23 million were replaced with surety bonds. See Note 9, "Commitments and Contingencies" for additional information. Revolving Credit Facility related issuance and amendment costs, net of amortization, were $7 million and $8 million as of September 30, 2023 and December 31, 2022, respectively. These costs are included in Other noncurrent assets on DT Midstream's Consolidated Statements of Financial Position and are being amortized over the remaining term of the Revolving Credit Facility. In June 2023, DT Midstream entered into an Amendment No. 2 to our Credit Agreement amending certain of the terms, including, among other things, the replacement of the interest rate provisions related to the Term Loan Facility from Eurodollar Rate to Term SOFR (as defined in the Credit Agreement). The Credit Agreement covering the Term Loan Facility and Revolving Credit Facility includes financial covenants that DT Midstream must maintain. These covenants restrict the ability of DT Midstream and our subsidiaries to incur additional indebtedness and guarantee indebtedness, create or incur liens, engage in mergers, consolidations, liquidations or dissolutions, sell, transfer or otherwise dispose of assets, make investments, acquisitions, loans or advances, pay dividends and distributions or repurchase capital stock, prepay, redeem or repurchase certain junior indebtedness, enter into agreements that limit the ability of the restricted subsidiaries to make distributions to DT Midstream or the ability of DT Midstream and our restricted subsidiaries to incur liens on assets and enter into certain transactions with affiliates. The Term Loan Facility requires the maintenance of a minimum debt service coverage ratio of 1.1 to 1, and the Revolving Credit Facility requires maintenance of (i) a maximum consolidated net leverage ratio of 5 to 1, and (ii) a minimum interest coverage ratio of no less than 2.5 to 1. The debt service coverage ratio means the ratio of annual consolidated EBITDA to debt service, as defined in the Credit Agreement. The consolidated net leverage ratio means the ratio of net debt determined in accordance with GAAP to annual consolidated EBITDA. The interest coverage ratio means the ratio of annual consolidated EBITDA to annual interest expense, as defined in the Credit Agreement. The Credit Agreement definition of annual consolidated EBITDA excludes EBITDA from equity method investees, but includes dividends and distributions from equity method investees .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES From time to time, DT Midstream is subject to legal, administrative and environmental proceedings before various courts, arbitration panels and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits and pending judicial matters. DT Midstream cannot predict the final disposition of such proceedings. DT Midstream regularly reviews legal matters and records provisions for claims that we can estimate and are considered probable of loss. The amount or range of reasonably possible losses is not anticipated to, either individually or in the aggregate, materially adversely affect DT Midstream’s business, financial condition and results of operations. Guarantees In certain limited circumstances, DT Midstream enters into contractual guarantees. DT Midstream may guarantee another entity's obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. DT Midstream did not have any guarantees of other parties' obligations as of September 30, 2023. Surety Bonds In certain limited circumstances, DT Midstream enters into contracts that require us to obtain external surety bonds to secure our payment and performance. DT Midstream agrees to indemnify the issuers of these surety bonds for amounts, if any, paid by them under these agreements. In the event that any surety bonds are called for non-performance, DT Midstream would be obligated to reimburse the issuer of the surety bond. The maximum potential indemnification under our surety bond agreements as of September 30, 2023 is $32 million. Vector Line of Credit DT Midstream is the lender under a revolving term credit facility to Vector, the borrower, in the amount of Canadian $70 million. The credit facility was executed in response to the passage of Canadian regulations requiring oil and gas pipelines to demonstrate their financial ability to respond to a catastrophic event and exists for the sole purpose of satisfying these regulations. Vector may only draw upon the facility if the funds are required to respond to a catastrophic event. The maximum potential payout as of September 30, 2023 is USD $52 million. The funding of a loan under the terms of the credit facility is considered remote. Environmental Contingencies In order to comply with certain state environmental regulations, DT Midstream has an obligation to restore pipeline right-of-way slope failures that may arise in the ordinary course of business in the Utica and Marcellus formations. DT Midstream conducted an evaluation, which was prioritized based on the severity and proximity of remaining locations, and used updated cost information to assess the adequacy of the estimate for the contingent liability accrual. Based on this evaluation, we recorded a reduction to the contingent liability accrual and decrease to operation and maintenance expense of $6 million during the three months ended September 30, 2023. As of September 30, 2023 and December 31, 2022, DT Midstream had accrued contingent liabilities of $13 million and $19 million, respectively, for future slope restoration expenditures. The accrual is included in Other current liabilities and Other liabilities in the Consolidated Statements of Financial Position. While restoration and continued evaluation is ongoing, DT Midstream believes the accrued amounts are sufficient to cover estimated future expenditures.

Segment and Related Information

Segment and Related Information	9 Months Ended
	Sep. 30, 2023
Segment Reporting [Abstract]
Segment and Related Information	SEGMENT AND RELATED INFORMATION DT Midstream sets strategic goals, allocates resources, and evaluates performance based on the following structure: The Pipeline segment owns and operates interstate and intrastate natural gas pipelines, storage systems, and natural gas gathering lateral pipelines. The segment also has interests in equity method investees that own and operate interstate natural gas pipelines. The Pipeline segment is also engaged in the transportation and storage of natural gas for intermediate and end user customers. During the three months ended March 31, 2023, DT Midstream completed the conversion of the Michigan System and began providing services under a new long-term dry gas transmission contract. During the three and nine months ended September 30, 2023, the Michigan System financial results are presented in the Pipeline segment. The prior year's comparative activity was for gathering services and therefore was not revised. The Gathering segment owns and operates gas gathering systems. The segment is engaged in collecting natural gas from points at or near customers’ wells for delivery to plants for treating, to gathering pipelines for further gathering, or to pipelines for transportation, as well as associated ancillary services, including compression, dehydration, gas treatment, water impoundment, water transportation, water disposal, and sand mining. Inter-segment billing for goods and services exchanged between segments is based upon contracted prices of the provider. Inter-segment billings were not significant for the three and nine months ended September 30, 2023 and 2022. The following table presents financial data by business segment: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Operating Revenues Pipeline $ 96 $ 87 $ 271 $ 247 Gathering 138 148 407 430 Total $ 234 $ 235 $ 678 $ 677 Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Net Income Attributable to DT Midstream by Segment Pipeline $ 64 $ 70 $ 185 $ 170 Gathering 27 43 78 115 Total $ 91 $ 113 $ 263 $ 285

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENT Dividend Declaration On November 1, 2023, DT Midstream announced that our Board of Directors declared a quarterly dividend of $0.69 per share of common stock. The dividend is payable to our stockholders of record as of December 18, 2023 and is expected to be paid on January 15, 2024.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The DT Midstream Consolidated Financial Statements and Notes to Consolidated Financial Statements are prepared under GAAP. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from DT Midstream’s estimates. DT Midstream believes the assumptions underlying these financial statements are reasonable. Certain prior-period amounts have been reclassified to conform to current-year presentation. In DT Midstream's opinion, the accompanying unaudited Consolidated Financial Statements include all adjustments, consisting of normal recurring adjustments, necessary to present a fair statement of our financial position as of September 30, 2023, results of operations for the three and nine months ended September 30, 2023 and 2022, statement of changes in stockholders' equity for the three and nine months ended September 30, 2023 and 2022, and cash flows for the nine months ended September 30, 2023 and 2022. The balance sheet as of December 31, 2022 was derived from audited annual financial statements but does not include all disclosures required by GAAP. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the year ending December 31, 2023. The Consolidated Financial Statements should be read in conjunction with DT Midstream's Consolidated Financial Statements and Notes to Consolidated Financial Statements included in DT Midstream's 2022 Annual Report on Form 10-K.
Principles of Consolidation	Principles of Consolidation DT Midstream consolidates all majority-owned subsidiaries and investments in entities in which we have a controlling influence. Non-controlled investments are accounted for using the equity method of accounting when DT Midstream is able to significantly influence the operating policies of the investee. When DT Midstream does not influence the operating policies of an investee, the equity investment is measured at fair value, if readily determinable, or if not readily determinable, at cost less impairment, if applicable. DT Midstream eliminates all intercompany balances and transactions. DT Midstream evaluates whether an entity is a VIE whenever reconsideration events occur. DT Midstream consolidates VIEs for which we are the primary beneficiary. If DT Midstream is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, DT Midstream considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. DT Midstream performs ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. DT Midstream owns an 85% interest in the Stonewall Gas Gathering VIE and is the primary beneficiary, therefore Stonewall Gas Gathering is consolidated. DT Midstream owns a 50% interest in the South Romeo VIE and is the primary beneficiary, therefore South Romeo is consolidated.
Cash and Cash Equivalents	Cash and Cash EquivalentsCash and cash equivalents include cash in banks and highly liquid money market investments with remaining maturities of three months or less, when purchased. Cash equivalents are stated at cost, which approximates fair value.
Financing Receivables	Financing Receivables Financing receivables are primarily composed of trade accounts receivable and notes receivable, which are stated at net realizable value. DT Midstream regularly monitors the credit quality of our financing receivables by reviewing counterparty credit quality indicators and monitoring for triggering events, such as a credit rating downgrade or bankruptcy. DT Midstream has three internal grades of credit quality, with internal grade 1 as the lowest risk and internal grade 3 as the highest risk. The related credit quality indicators and risk ratings utilized to develop the internal grades have been updated through September 30, 2023. As of September 30, 2023, the Notes receivable — related party of $4 million, which originated prior to 2021, was classified as internal grade 1. There are no notes receivable on nonaccrual status and no past due financing receivables as of September 30, 2023.

Description of the Business a_2

Description of the Business and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the major line items in the Consolidated Statements of Financial Position for consolidated VIEs as of September 30, 2023 and December 31, 2022. All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. The assets and liabilities of consolidated VIEs that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIEs' obligations have been excluded from the table below. Amounts for consolidated VIEs are as follows: September 30, December 31, 2023 2022 (millions) ASSETS (a) Cash $ 11 $ 27 Accounts receivable 8 9 Other current assets 1 3 Intangible assets, net 487 498 Property, plant and equipment, net 394 403 Goodwill 25 25 $ 926 $ 965 LIABILITIES (a) Accounts payable and other current liabilities $ 2 $ 4 Other noncurrent liabilities 4 4 $ 6 $ 8 _____________________________________ (a) Amounts shown are 100% of the consolidated VIEs' assets and liabilities.
Schedule of Equity Method Investments	Equity method investees are described below: Investments As of % Owned As of September 30, December 31, September 30, December 31, Equity Method Investee 2023 2022 2023 2022 (millions) NEXUS $ 916 $ 1,313 50% 50% Vector 137 135 40% 40% Millennium 729 752 52.5% 52.5% Total investments in equity method investees $ 1,782 $ 2,200 The following table presents summarized financial information of DT Midstream's non-consolidated equity method investees. The amounts included below represent 100% of the results of continuing operations of such entities, including the portion owned by other parties. Summarized income statement data is as follows: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Operating revenues $ 201 $ 194 $ 611 $ 583 Operating expenses 94 94 282 282 Net Income $ 91 $ 93 $ 292 $ 277

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following is the summary of the carrying value of goodwill: September 30, December 31, 2023 2022 (millions) Pipeline $ 53 $ 53 Gathering 420 420 Total goodwill $ 473 $ 473

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following is a summary of revenues disaggregated by segment: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Pipeline (a) $ 96 $ 87 $ 271 $ 247 Gathering 138 148 407 430 Total operating revenues $ 234 $ 235 $ 678 $ 677 __________________________________ (a) Includes revenues outside the scope of Topic 606 primarily related to contracts accounted for as leases of $2 million and $3 million for the three months ended September 30, 2023 and 2022, respectively, and $5 million and $7 million for the nine months ended September 30, 2023 and 2022, respectively.
Summary of Contact Liability Activity	The following is a summary of contract liability activity: 2023 (millions) Balance as of January 1 $ 32 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 62 Revenue recognized that was included in the balance at the beginning of the period (3) Balance as of September 30 $ 91
Revenue Expected to be Recognized in Future Periods	The following table presents contract liability amounts as of September 30, 2023 that are expected to be recognized as revenue in future periods: (millions) Remainder of 2023 $ 3 2024 13 2025 13 2026 13 2027 13 2028 and thereafter 36 Total $ 91 The following table presents revenue amounts related to fixed consideration associated with unsatisfied performance obligations as of September 30, 2023 that are expected to be recognized as revenue in future periods: (millions) Remainder of 2023 $ 27 2024 129 2025 133 2026 103 2027 71 2028 and thereafter 247 Total $ 710

Earnings Per Share and Divide_2

Earnings Per Share and Dividends (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Earnings Per Share	The following is a reconciliation of DT Midstream's basic and diluted earnings per share calculation: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions, except per share amounts) Basic and Diluted Earnings per Common Share Net Income Attributable to DT Midstream $ 91 $ 113 $ 263 $ 285 Average number of common shares outstanding — basic 97.0 96.7 96.9 96.7 Incremental shares attributable to: Average dilutive restricted stock units and performance share awards 0.5 0.3 0.5 0.3 Average number of common shares outstanding — diluted 97.5 97.0 97.4 97.0 Basic Earnings per Common Share $ 0.94 $ 1.17 $ 2.72 $ 2.94 Diluted Earnings per Common Share $ 0.94 $ 1.16 $ 2.70 $ 2.94
Schedule of Cash Dividends Declared	DT Midstream declared the following cash dividends: Dividends Declared Dividend Amount Dividend Payment Date (quarter ended) (per-share) (millions) 2022 March 31 $ 0.64 $ 62 April 2022 June 30 $ 0.64 $ 62 July 2022 September 30 $ 0.64 $ 62 October 2022 December 31 $ 0.64 $ 62 January 2023 2023 March 31 $ 0.69 $ 67 April 2023 June 30 $ 0.69 $ 67 July 2023 September 30 $ 0.69 $ 67 October 2023

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Carrying Amount of Fair Value of Financial Instruments	The following table presents the carrying amount and fair value of financial instruments: September 30, 2023 December 31, 2022 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (millions) Cash equivalents (a) $ 13 $ — $ 13 $ — $ — $ — $ — $ — Long-term notes receivable — related party 4 — — 4 4 — — 4 Short-term borrowings (a) 125 — 125 — 330 — 330 — Long-term debt (b) $ 3,064 $ — $ 2,693 $ — $ 3,059 $ — $ 2,701 $ — ______________________________________ (a) Short-term borrowings and money market cash equivalents are stated at cost, which approximates fair value. (b) Carrying value represents principal of $3,099 million, net of unamortized debt discounts and issuance costs.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Schedule of Long-term Debt Outstanding	DT Midstream's long-term debt outstanding included: Maturity September 30, December 31, Title Type Interest Rate Date (d) 2023 2022 (millions) 2029 Notes Senior Notes (a) 4.125% 2029 $ 1,100 $ 1,100 2031 Notes Senior Notes (a) 4.375% 2031 1,000 1,000 2032 Notes Senior Secured Notes (b) 4.300% 2032 600 600 Term Loan Facility Term Loan Facility Variable (c) 2028 399 399 Long-term debt principal 3,099 3,099 Unamortized debt discount (2) (3) Unamortized debt issuance costs (33) (37) Long-term debt $ 3,064 $ 3,059 ______________________________ (a) Interest payable semi-annually in arrears each June 15 and December 15. (b) Interest payable semi-annually in arrears each April 15 and October 15. (c) Variable rate is SOFR plus 2.11% for a one-month interest period as of September 30, 2023. (d) DT Midstream does not have any scheduled debt maturities until 2028.
Schedule of Availability Under the Revolving Credit Facility	The following table presents the availability under the Revolving Credit Facility: September 30, 2023 (millions) Total availability Revolving Credit Facility, expiring October 2027 $ 1,000 Amounts outstanding Revolving Credit Facility borrowings 125 Letters of credit 16 141 Net availability $ 859

Segment and Related Informati_2

Segment and Related Information (Tables)	9 Months Ended
	Sep. 30, 2023
Segment Reporting [Abstract]
Schedule of Financial Data by Business Segment	The following table presents financial data by business segment: Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Operating Revenues Pipeline $ 96 $ 87 $ 271 $ 247 Gathering 138 148 407 430 Total $ 234 $ 235 $ 678 $ 677 Three Months Ended Nine Months Ended September 30, September 30, 2023 2022 2023 2022 (millions) Net Income Attributable to DT Midstream by Segment Pipeline $ 64 $ 70 $ 185 $ 170 Gathering 27 43 78 115 Total $ 91 $ 113 $ 263 $ 285

Description of the Business a_3

Description of the Business and Basis of Presentation (Narrative) (Details)	1 Months Ended		9 Months Ended
	May 31, 2023 USD ($)	Oct. 31, 2022 USD ($)	Sep. 30, 2023 USD ($) segment	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items]
Number of segments | segment			2
Amount by which the share of the underlying equity in the net assets exceeds the carrying amount			$ 356,000,000		$ 368,000,000
Undistributed earnings from equity method investments			0		$ 43,000,000
Payments to acquire equity method investments			$ 6,000,000	$ 4,000,000
NEXUS Senior Unsecured Notes | Senior Notes
Related Party Transaction [Line Items]
Long-term debt issued	$ 750,000,000
Interest Rate	5.52%
Proceeds from issuance of debt	$ 371,000,000
Millennium
Related Party Transaction [Line Items]
Amount by which the share of the underlying equity in the net assets exceeds the carrying amount		$ 343,000,000
Payments to acquire equity method investments		$ 552,000,000
Additional ownership interest acquired		0.2625
Ownership percentage		52.50%	52.50%		52.50%
Variable Interest Entity, Primary Beneficiary, Stonewall Gas Gathering
Related Party Transaction [Line Items]
VIE ownership percentage			85%
Variable Interest Entity, Primary Beneficiary, South Romeo
Related Party Transaction [Line Items]
VIE ownership percentage			50%

Description of the Business a_4

Description of the Business and Basis of Presentation (Consolidated VIEs) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
ASSETS
Cash	$ 30	$ 61
Accounts receivable	146	161
Intangible assets, net	1,982	2,025
Property, plant and equipment, net	4,348	3,806
Goodwill	473	473
Total Assets	8,862	8,833
LIABILITIES
Other noncurrent liabilities	1,153	1,006
Total Liabilities	4,641	4,679
Variable interest entity, primary beneficiary
ASSETS
Cash	11	27
Accounts receivable	8	9
Other current assets	1	3
Intangible assets, net	487	498
Property, plant and equipment, net	394	403
Goodwill	25	25
Total Assets	926	965
LIABILITIES
Accounts payable and other current liabilities	2	4
Other noncurrent liabilities	4	4
Total Liabilities	$ 6	$ 8

Description of the Business a_5

Description of the Business and Basis of Presentation (Equity Method Investees) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Oct. 31, 2022
Schedule of Equity Method Investments [Line Items]
Investments As of	$ 1,782	$ 2,200
NEXUS
Schedule of Equity Method Investments [Line Items]
Investments As of	$ 916	$ 1,313
% Owned As of	50%	50%
Vector
Schedule of Equity Method Investments [Line Items]
Investments As of	$ 137	$ 135
% Owned As of	40%	40%
Millennium
Schedule of Equity Method Investments [Line Items]
Investments As of	$ 729	$ 752
% Owned As of	52.50%	52.50%	52.50%

Description of the Business a_6

Description of the Business and Basis of Presentation (Summarized Income Statement Data) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 234			$ 235			$ 678	$ 677
Net Income	94	$ 94	$ 84	116	$ 94	$ 84	272	294
Equity method investment, non-consolidated investees
Schedule of Equity Method Investments [Line Items]
Operating revenues	201			194			611	583
Operating expenses	94			94			282	282
Net Income	$ 91			$ 93			$ 292	$ 277

Significant Accounting Polici_3

Significant Accounting Policies (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) internal_grade	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) internal_grade	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Financing Receivable, Past Due [Line Items]
Number of internal grades of credit quality | internal_grade	3		3
Specific review of probable future collections based on receivable balances, threshold duration			30 days
Uncollectible expense (recovery)	$ 0	$ 0	$ 0	$ 0
Allowance for expected credit loss related to accounts receivable	0		0		$ 0
Past due
Financing Receivable, Past Due [Line Items]
Financing receivables	0		0
Notes receivable
Financing Receivable, Past Due [Line Items]
Financing receivables on nonaccrual status	0		0
Notes receivable | Internal grade 1 | Related Party
Financing Receivable, Past Due [Line Items]
Financing receivable originated prior to 2021	$ 4,000,000		$ 4,000,000

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 473	$ 473
Operating segments | Pipeline
Goodwill [Line Items]
Goodwill	53	53
Operating segments | Gathering
Goodwill [Line Items]
Goodwill	$ 420	$ 420

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 234	$ 235	$ 678	$ 677
Pipeline
Disaggregation of Revenue [Line Items]
Total operating revenues	96	87	271	247
Lease revenue outside scope of Topic 606	2	3	5	7
Gathering
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 138	$ 148	$ 407	$ 430

Revenue (Contract Liabilities)

Revenue (Contract Liabilities) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Change In Contract With Customer, Liability [Roll Forward]
Beginning Balance	$ 32
Increases due to cash received or receivable, excluding amounts recognized as revenue during the period	62
Revenue recognized that was included in the balance at the beginning of the period	(3)
Ending Balance	$ 91

Revenue (Expected Recognition o

Revenue (Expected Recognition of Contract Liabilities) (Details) $ in Millions	Sep. 30, 2023 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 91
Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	710
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3
Remaining performance obligation, expected timing of satisfaction	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01 | Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 27
Remaining performance obligation, expected timing of satisfaction	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01 | Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 129
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01 | Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 133
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01 | Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 103
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01 | Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 71
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 36
Remaining performance obligation, expected timing of satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01 | Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 247
Remaining performance obligation, expected timing of satisfaction

Revenue (Expected Timing of Per

Revenue (Expected Timing of Performance Obligation Satisfaction Related to Fixed Consideration) (Details) $ in Millions	Sep. 30, 2023 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 91
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3
Remaining performance obligation, expected timing of satisfaction	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 36
Remaining performance obligation, expected timing of satisfaction
Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 710
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 27
Remaining performance obligation, expected timing of satisfaction	3 months
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 129
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 133
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 103
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 71
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 247
Remaining performance obligation, expected timing of satisfaction

Revenue (Narrative) (Details)

Revenue (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Capitalized contract cost, net	$ 18		$ 18		$ 19
Capitalized contract cost, amortization expense (less than)	$ 1	$ 1	$ 1	$ 1

Earnings Per Share and Divide_3

Earnings Per Share and Dividends (Reconciliation of Basic and Diluted Earnings Per Share Calculation) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Basic and Diluted Earnings per Common Share
Net Income Attributable to DT Midstream	$ 91	$ 113	$ 263	$ 285
Average number of common shares outstanding — basic (in shares)	97	96.7	96.9	96.7
Incremental shares attributable to:
Average dilutive restricted stock units and performance share awards (in shares)	0.5	0.3	0.5	0.3
Average number of common shares outstanding — diluted (in shares)	97.5	97	97.4	97
Basic earnings per common share (in dollars per share)	$ 0.94	$ 1.17	$ 2.72	$ 2.94
Diluted earnings per common share (in dollars per share)	$ 0.94	$ 1.16	$ 2.70	$ 2.94

Earnings Per Share and Divide_4

Earnings Per Share and Dividends (Dividends Declared) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Earnings Per Share [Abstract]
Quarterly Dividend (in dollars per share)	$ 0.69	$ 0.69	$ 0.69	$ 0.64	$ 0.64	$ 0.64	$ 0.64
Dividend Amount	$ 67	$ 67	$ 67	$ 62	$ 62	$ 62	$ 62

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Estimated annual effective tax rate	26%	6%	27%	18%

Fair Value (Details)

Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt principal	$ 3,099	$ 3,099
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	125	330
Long-term debt	3,064	3,059
Carrying Amount | Related Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term notes receivable - related party	4	4
Carrying Amount | Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	13	0
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Long-term debt	0	0
Fair Value | Level 1 | Related Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term notes receivable - related party	0	0
Fair Value | Level 1 | Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0	0
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	125	330
Long-term debt	2,693	2,701
Fair Value | Level 2 | Related Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term notes receivable - related party	0	0
Fair Value | Level 2 | Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	13	0
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Long-term debt	0	0
Fair Value | Level 3 | Related Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term notes receivable - related party	4	4
Fair Value | Level 3 | Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 0	$ 0

Debt (Narrative) (Details)

Debt (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)	Apr. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Line Of Credit Facility [Line Items]
Debt amendment cost			$ 8
Debt service coverage ratio	8.3
Consolidated net leverage ratio	2.4
Interest coverage ratio	7.8
Performance surety bonds
Line Of Credit Facility [Line Items]
Performance bonds outstanding		$ 23
Secured Revolving Credit Facility expiring June 2026 | Revolving Credit Facility
Line Of Credit Facility [Line Items]
Fees incurred	$ 7
Maximum consolidated net leverage ratio	5
Minimum interest coverage ratio	2.5
Variable rate Term Loan Facility due 2028
Line Of Credit Facility [Line Items]
Minimum debt service coverage ratio	1.1

Debt (Long-term Debt Outstandin

Debt (Long-term Debt Outstanding) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt principal	$ 3,099	$ 3,099
Unamortized debt discount	(2)	(3)
Unamortized debt issuance costs	(33)	(37)
Long-term debt	$ 3,064	3,059
4.125% Senior Notes due 2029 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.125%
Long-term debt principal	$ 1,100	1,100
4.375% Senior Notes due 2031 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.375%
Long-term debt principal	$ 1,000	1,000
4.300% Senior Secured Notes due 2032 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.30%
Long-term debt principal	$ 600	600
Variable rate Term Loan Facility due 2028
Debt Instrument [Line Items]
Long-term debt principal	$ 399	$ 399
Variable rate Term Loan Facility due 2028 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.11%

Debt (Availability Under the Re

Debt (Availability Under the Revolving Credit Facility) (Details) - Revolving Credit Facility, expiring October 2027 $ in Millions	Sep. 30, 2023 USD ($)
Line Of Credit Facility [Line Items]
Amounts outstanding	$ 141
Net availability	859
Revolving Credit Facility
Line Of Credit Facility [Line Items]
Total availability	1,000
Amounts outstanding	125
Letter of credit
Line Of Credit Facility [Line Items]
Amounts outstanding	$ 16

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) $ in Millions, $ in Millions	3 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2023 CAD ($)	Dec. 31, 2022 USD ($)
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies, revision in estimates	$ 6
Accrued contingent liabilities	13		$ 19
Performance surety bonds
Loss Contingencies [Line Items]
Guarantee value	32
Revolving Term Credit Facility | Vector
Loss Contingencies [Line Items]
Financing receivables		$ 70
Maximum potential payout under line of credit	$ 52

Segment and Related Informati_3

Segment and Related Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	$ 234	$ 235	$ 678	$ 677
Net Income Attributable to DT Midstream	91	113	263	285
Pipeline
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	96	87	271	247
Net Income Attributable to DT Midstream	64	70	185	170
Gathering
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating revenues	138	148	407	430
Net Income Attributable to DT Midstream	$ 27	$ 43	$ 78	$ 115

Subsequent Event (Details)

Subsequent Event (Details) - $ / shares		3 Months Ended
	Nov. 01, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Subsequent Event [Line Items]
Dividends declared on common stock (in dollars per share)		$ 0.69	$ 0.69	$ 0.69	$ 0.64	$ 0.64	$ 0.64	$ 0.64
Subsequent Event
Subsequent Event [Line Items]
Dividends declared on common stock (in dollars per share)	$ 0.69