Regulatory Assets and Liabilities - NWP (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets	$ 666	$ 622
Regulatory Liability [Line Items]
Regulatory Liability, Current	85	77
Regulatory Liabilities	1,385	1,365
Northwest Pipeline LLC [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	6	2
Regulatory Assets, Noncurrent	49	36
Regulatory Assets	55	38
Regulatory Liability [Line Items]
Regulatory Liability, Current	20	21
Regulatory Liabilities, Noncurrent	233	252
Regulatory Liabilities	253	273
Northwest Pipeline LLC [Member] | Deferred Income Tax Charge
Regulatory Liability [Line Items]
Regulatory Liability, Current	20	20
Regulatory Liabilities, Noncurrent	160	179
Northwest Pipeline LLC [Member] | Deferred Fuel Costs
Regulatory Liability [Line Items]
Regulatory Liability, Current	0	1
Northwest Pipeline LLC [Member] | Postretirement Benefit Costs
Regulatory Liability [Line Items]
Regulatory Liabilities, Noncurrent	43	42
Northwest Pipeline LLC [Member] | Removal Costs
Regulatory Liability [Line Items]
Regulatory Liabilities, Noncurrent	30	31
Northwest Pipeline LLC [Member] | Deferred Fuel Costs
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	4	0
Northwest Pipeline LLC [Member] | Levelized Depreciation
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	2	2
Regulatory Assets, Noncurrent	7	10
Northwest Pipeline LLC [Member] | Deferred Taxes On Equity Funds Used During Construction
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent	4	4
Northwest Pipeline LLC [Member] | Washington State Climate Commitment Act
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent	$ 38	$ 22