DEBT DEBT (Details) $ in Thousands		3 Months Ended	6 Months Ended
	Jul. 12, 2022 USD ($) Rate	Jun. 30, 2022 USD ($) Rate	Jun. 30, 2022 USD ($) Rate	Jul. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Total debt		$ 13,876,709	$ 13,876,709		$ 13,756,709
Unamortized portion of terminated swaps		10,737	10,737		11,596
Unamortized debt issuance costs and discounts		(118,940)	(118,940)		(124,855)
Current maturities of long-term debt		(895,814)	(895,814)		(895,814)
Long-term debt		12,872,692	12,872,692		12,747,636
Asset Acquisition, Consideration Transferred		30,000
$2.5 Billion Credit Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		2,500,000	$ 2,500,000
Debt Instrument, Covenant Description			Among other things, beginning in June 2022, these covenants include maintaining a ratio of consolidated net indebtedness to adjusted EBITDA (EBITDA, as defined in our $2.5 Billion Credit Agreement, adjusted for all noncash charges and increased for projected EBITDA from certain lender-approved capital expansion projects). In the first quarter 2022, we acquired assets for $30 million, which allowed us to elect an acquisition adjustment period under our $2.5 Billion Credit Agreement and, as a result, increased our leverage ratio covenant to 5.5 to 1 for the first quarter 2022 and the two following quarters. Thereafter, the covenant will decrease to 5.0 to 1.
Line of Credit Facility, Amount Outstanding		$ 0	$ 0
Indebtedness To Adjusted EBITDA Current		3.9	3.9
Indebtedness To Adjusted EBITDA Maximum		5.0	5.0
Indebtedness To Adjusted EBITDA From Acquisitions Maximum		5.5	5.5
Line of Credit Facility Sublimit		$ 100,000	$ 100,000
Line of Credit Facility Swingline Subfacility		200,000	200,000
Line of Credit Facility Option To Increase Borrowing Capacity		$ 1,000,000	$ 1,000,000
Line of Credit Facility, Interest Rate Description			Borrowings, if any, will accrue at Term SOFR plus an applicable margin based on our credit ratings at the time of determination plus an adjustment of 10 basis points. Under our current credit ratings, the applicable margin on any borrowings would be 110 basis points.
Line Of Credit Facility, Annual Facility Fee Description			the applicable rate is 15 basis points.
Guardian Term Loan Agreement
Debt Instrument [Line Items]
Debt Instrument, Covenant Description		Guardian Term Loan Agreement - In June 2022, Guardian Pipeline entered into a $120 million senior unsecured Term Loan Agreement. The Guardian Term Loan Agreement matures in June 2025, and bears interest at Term SOFR plus an applicable margin based on Guardian Pipeline’s credit rating at the time of determination plus an adjustment of 10 basis points. Under Guardian Pipeline’s current credit ratings, the applicable margin is 112.5 basis points. The Guardian Term Loan Agreement allows prepayment of all or any portion outstanding without penalty or premium. During the second quarter 2022, Guardian Pipeline drew the full $120 million available under the agreement and used the proceeds to repay intercompany debt with ONEOK. The Guardian Term Loan Agreement contains certain affirmative and negative covenants, as well as customary events of default, the occurrence of which could result in a termination of lenders’ commitments and the accelerations of all of Guardian Pipeline’s obligations thereunder. Guardian Pipeline is in compliance with all covenants under the Guardian Term Loan Agreement.
Guardian Pipeline [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate Description			bears interest at Term SOFR plus an applicable margin based on Guardian Pipeline’s credit rating at the time of determination plus an adjustment of 10 basis points. Under Guardian Pipeline’s current credit ratings, the applicable margin is 112.5 basis points.
Notes Payable due 2025 | Guardian Pipeline [Member]
Debt Instrument [Line Items]
Total debt					0
Notes Payable due 2025 | Guardian Pipeline [Member] | Variable rate
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 120,000	$ 120,000
Total debt		120,000	120,000
Subsidiary Issuer [Member] | 3.375% Notes Payable due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 900,000	$ 900,000
Interest Rate (in hundredths) | Rate		3.375%	3.375%
Total debt		$ 895,814	$ 895,814		895,814
Subsidiary Issuer [Member] | 3.375% Notes Payable due 2022 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 900,000
Interest Rate (in hundredths) | Rate	3.375%
Repayments of Debt	$ 895,800
Debt Instrument, Redemption Price, Percentage	100.00%
Subsidiary Issuer [Member] | 5.0% Notes Payable due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 425,000	$ 425,000
Interest Rate (in hundredths) | Rate		5.00%	5.00%
Total debt		$ 425,000	$ 425,000		425,000
Subsidiary Issuer [Member] | 4.9% Notes Payable due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 500,000	$ 500,000
Interest Rate (in hundredths) | Rate		4.90%	4.90%
Total debt		$ 500,000	$ 500,000		500,000
Subsidiary Issuer [Member] | 6.65% Notes Payable due 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 600,000	$ 600,000
Interest Rate (in hundredths) | Rate		6.65%	6.65%
Total debt		$ 600,000	$ 600,000		600,000
Subsidiary Issuer [Member] | 6.85% Notes Payable due 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 600,000	$ 600,000
Interest Rate (in hundredths) | Rate		6.85%	6.85%
Total debt		$ 600,000	$ 600,000		600,000
Subsidiary Issuer [Member] | 6.125% Notes Payable due 2041 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 650,000	$ 650,000
Interest Rate (in hundredths) | Rate		6.125%	6.125%
Total debt		$ 650,000	$ 650,000		650,000
Subsidiary Issuer [Member] | 6.2% Notes Payable due 2043 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 400,000	$ 400,000
Interest Rate (in hundredths) | Rate		6.20%	6.20%
Total debt		$ 400,000	$ 400,000		400,000
Parent Company
Debt Instrument [Line Items]
Commercial Paper		0	0		0
Parent Company | Subsequent Event [Member]
Debt Instrument [Line Items]
Commercial Paper				$ 860,000
Parent Company | 7.5% Notes Payable due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 500,000	$ 500,000
Interest Rate (in hundredths) | Rate		7.50%	7.50%
Total debt		$ 500,000	$ 500,000		500,000
Parent Company | 2.75% Notes Payable due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 500,000	$ 500,000
Interest Rate (in hundredths) | Rate		2.75%	2.75%
Total debt		$ 500,000	$ 500,000		500,000
Parent Company | 2.2% Notes Payable due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 400,000	$ 400,000
Interest Rate (in hundredths) | Rate		2.20%	2.20%
Total debt		$ 387,000	$ 387,000		387,000
Parent Company | 5.85% Notes Payable due 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 600,000	$ 600,000
Interest Rate (in hundredths) | Rate		5.85%	5.85%
Total debt		$ 600,000	$ 600,000		600,000
Parent Company | 4.0% Notes Payable due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 500,000	$ 500,000
Interest Rate (in hundredths) | Rate		4.00%	4.00%
Total debt		$ 500,000	$ 500,000		500,000
Parent Company | 4.55% Notes Payable due 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 800,000	$ 800,000
Interest Rate (in hundredths) | Rate		4.55%	4.55%
Total debt		$ 800,000	$ 800,000		800,000
Parent Company | 6.875% Notes Payable due 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 100,000	$ 100,000
Interest Rate (in hundredths) | Rate		6.875%	6.875%
Total debt		$ 100,000	$ 100,000		100,000
Parent Company | 4.35% Notes Payable due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 700,000	$ 700,000
Interest Rate (in hundredths) | Rate		4.35%	4.35%
Total debt		$ 700,000	$ 700,000		700,000
Parent Company | 3.4% Notes Payable due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 750,000	$ 750,000
Interest Rate (in hundredths) | Rate		3.40%	3.40%
Total debt		$ 714,251	$ 714,251		714,251
Parent Company | 3.1% Notes Payable due 2030 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 850,000	$ 850,000
Interest Rate (in hundredths) | Rate		3.10%	3.10%
Total debt		$ 780,093	$ 780,093		780,093
Parent Company | 6.35% Notes Payable due 2031 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 600,000	$ 600,000
Interest Rate (in hundredths) | Rate		6.35%	6.35%
Total debt		$ 600,000	$ 600,000		600,000
Parent Company | 6.0% Notes Payable due 2035 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 400,000	$ 400,000
Interest Rate (in hundredths) | Rate		6.00%	6.00%
Total debt		$ 400,000	$ 400,000		400,000
Parent Company | 4.95% Notes Payable due 2047 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 700,000	$ 700,000
Interest Rate (in hundredths) | Rate		4.95%	4.95%
Total debt		$ 689,006	$ 689,006		689,006
Parent Company | 5.2% Notes Payable due 2048 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 1,000,000	$ 1,000,000
Interest Rate (in hundredths) | Rate		5.20%	5.20%
Total debt		$ 1,000,000	$ 1,000,000		1,000,000
Parent Company | 4.45% Notes Payable due 2049 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 750,000	$ 750,000
Interest Rate (in hundredths) | Rate		4.45%	4.45%
Total debt		$ 672,530	$ 672,530		672,530
Parent Company | 4.5% Notes Payable due 2050 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 500,000	$ 500,000
Interest Rate (in hundredths) | Rate		4.50%	4.50%
Total debt		$ 443,015	$ 443,015		443,015
Parent Company | 7.15% Notes Payable due 2051 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 300,000	$ 300,000
Interest Rate (in hundredths) | Rate		7.15%	7.15%
Total debt		$ 300,000	$ 300,000		$ 300,000