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Aggregate dividends paid during the period for each share of common stock outstanding.

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EQUITY (Details) $ / shares in Units, $ in Millions		1 Months Ended	3 Months Ended						9 Months Ended
EQUITY (Details) $ / shares in Units, $ in Millions	Sep. 10, 2026 USD ($)	Oct. 28, 2026 $ / shares	Sep. 30, 2026 USD ($) $ / shares	Jun. 30, 2026 $ / shares	Mar. 31, 2026 $ / shares	Sep. 30, 2025 $ / shares	Jun. 30, 2025 $ / shares	Mar. 31, 2025 $ / shares	Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)
Debt Instrument [Line Items]
Cash contribution									$ 9,000	$ 0
Noncash income tax benefit resulting from equity transaction			$ 336
Annual effective tax rate									14.20%
Common stock dividends (in dollars per share) \| $ / shares			$ 1.07	$ 1.07	$ 1.07	$ 1.03	$ 1.03	$ 1.03
Subsequent Event
Debt Instrument [Line Items]
Common stock, dividends, declared (in dollars per share) \| $ / shares		$ 1.07
ONEOK Holdings \| Common Class B \| Minimum
Debt Instrument [Line Items]
Common stock, dividend rights percentage	15.00%
ONEOK Holdings \| Common Class B \| Maximum
Debt Instrument [Line Items]
Common stock, dividend rights percentage	20.00%
ONEOK Holdings
Debt Instrument [Line Items]
Leverage ratio	4.5
ONEOK Holdings \| Common Class B
Debt Instrument [Line Items]
Operating agreement, purchase of shares, investment balance maximum	$ 200
Percent of buyout amount	115.00%
Required purchase percent of buyout amount	115.00%
ONEOK Holdings \| Apollo \| Common Class B
Debt Instrument [Line Items]
Cash contribution	$ 9,000