EBP Asset rollforward and B.S. classification (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Amounts included in regulatory liabilities associated with Transco and Northwest Pipeline:
Net regulatory liabilities	$ 123	$ 130
Pension Benefits [Member]
Change in plan assets:
Fair value of plan assets at beginning of year	1,117	1,336
Actual return on plan assets	120	(132)
Employer contributions	1	3
Plan participants’ contributions	0	0
Benefits paid	(71)	(78)
Settlements	0	(12)
Net increase (decrease) in fair value of plan assets	50	(219)
Fair value of plan assets at end of year	1,167	1,117
Funded status — overfunded (underfunded)	161	177
Amounts recognized in the Consolidated Balance Sheet:
Noncurrent assets	187	201
Current liabilities	(4)	(2)
Noncurrent liabilities	(22)	(22)
Funded status - overfunded (underfunded)	161	177
Accumulated benefit obligation	998	930
Plans with a projected benefit obligation in excess of plan assets:
Projected benefit obligation	26	24
Plans with an accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	24	22
Fair value of plan assets	0	0
Amounts recognized in Accumulated other comprehensive income (loss):
Net actuarial gain (loss)	(45)	(45)
Other Postretirement Benefits [Member]
Change in plan assets:
Fair value of plan assets at beginning of year	253	287
Actual return on plan assets	17	(27)
Employer contributions	3	3
Plan participants’ contributions	2	2
Benefits paid	(13)	(12)
Settlements	0	0
Net increase (decrease) in fair value of plan assets	9	(34)
Fair value of plan assets at end of year	262	253
Funded status — overfunded (underfunded)	117	101
Amounts recognized in the Consolidated Balance Sheet:
Noncurrent assets	120	105
Current liabilities	(3)	(4)
Noncurrent liabilities	0	0
Funded status - overfunded (underfunded)	117	101
Amounts recognized in Accumulated other comprehensive income (loss):
Net actuarial gain (loss)	$ 19	$ 18