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Acquisitions and Other Transactions (Whistler Joint Venture Transaction) (Details) - USD ($) $ in Millions		9 Months Ended
	May 29, 2024	Sep. 30, 2025	Sep. 30, 2024
Business Combination [Line Items]
Investments - redemptions, repayments, return of capital and sales proceeds		$ 143	$ 138
WPC Parent, LLC
Business Combination [Line Items]
Gain (Loss) on Disposition of Stock in Subsidiary or Equity Method Investee	$ 151
Investments - redemptions, repayments, return of capital and sales proceeds	$ 134
WPC Parent, LLC | Enbridge Inc.
Business Combination [Line Items]
Equity method investment, ownership percentage	19.00%
WPC Parent, LLC | MPLX LP [Member]
Business Combination [Line Items]
Equity method investment, ownership percentage	30.40%
Whistler Pipeline LLC [Member] | MPLX LP [Member]
Business Combination [Line Items]
Equity method investment, ownership percentage	37.50%

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