Segment Disclosures Reconciliation of Segment Revenues to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment revenues
Revenues	$ 2,283	$ 1,781	$ 4,895	$ 3,694
Intersegment Elimination [Member]
Segment revenues
Revenues	(120)	(58)	(241)	(119)
Operating Segments [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	900	834	1,812	1,720
Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	399	356	792	745
Operating Segments [Member] | West [Member]
Segment revenues
Revenues	1,052	640	2,417	1,331
Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	52	9	115	17
Service [Member]
Segment revenues
Revenues	1,460	1,446	2,912	2,920
Service [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	811	783	1,633	1,597
Service [Member] | Northeast G And P [Member]
Segment revenues
Revenues	364	342	711	686
Service [Member] | West [Member]
Segment revenues
Revenues	280	316	559	627
Service [Member] | Other [Member]
Segment revenues
Revenues	5	5	9	10
Service [Member] | Intersegment Elimination [Member]
Segment revenues
Revenues	(35)	(28)	(66)	(60)
Service [Member] | Intersegment Elimination [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	(12)	(12)	(24)	(27)
Service [Member] | Intersegment Elimination [Member] | Northeast G And P [Member]
Segment revenues
Revenues	(9)	(12)	(20)	(26)
Service [Member] | Intersegment Elimination [Member] | West [Member]
Segment revenues
Revenues	(11)	0	(16)	0
Service [Member] | Intersegment Elimination [Member] | Other [Member]
Segment revenues
Revenues	(3)	(4)	(6)	(7)
Service [Member] | Operating Segments [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	823	795	1,657	1,624
Service [Member] | Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	373	354	731	712
Service [Member] | Operating Segments [Member] | West [Member]
Segment revenues
Revenues	291	316	575	627
Service [Member] | Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	8	9	15	17
NonRegulated Service Commodity Consideration [Member]
Segment revenues
Revenues	51	25	100	53
NonRegulated Service Commodity Consideration [Member] | Intersegment Elimination [Member]
Segment revenues
Revenues	0	0	0	0
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	10	3	21	8
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	2	1	5	3
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | West [Member]
Segment revenues
Revenues	39	21	74	42
NonRegulated Service Commodity Consideration [Member] | Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	0	0	0	0
Product [Member]
Segment revenues
Revenues	772	310	1,883	721
Product [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	47	29	87	70
Product [Member] | Northeast G And P [Member]
Segment revenues
Revenues	8	(8)	12	15
Product [Member] | West [Member]
Segment revenues
Revenues	696	289	1,714	636
Product [Member] | Other [Member]
Segment revenues
Revenues	21	0	70	0
Product [Member] | Intersegment Elimination [Member]
Segment revenues
Revenues	(85)	(30)	(175)	(59)
Product [Member] | Intersegment Elimination [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	(20)	(7)	(47)	(18)
Product [Member] | Intersegment Elimination [Member] | Northeast G And P [Member]
Segment revenues
Revenues	(16)	(9)	(44)	(15)
Product [Member] | Intersegment Elimination [Member] | West [Member]
Segment revenues
Revenues	(26)	(14)	(54)	(26)
Product [Member] | Intersegment Elimination [Member] | Other [Member]
Segment revenues
Revenues	(23)	0	(30)	0
Product [Member] | Operating Segments [Member] | Transmission And Gulf Of Mexico [Member]
Segment revenues
Revenues	67	36	134	88
Product [Member] | Operating Segments [Member] | Northeast G And P [Member]
Segment revenues
Revenues	24	1	56	30
Product [Member] | Operating Segments [Member] | West [Member]
Segment revenues
Revenues	722	303	1,768	662
Product [Member] | Operating Segments [Member] | Other [Member]
Segment revenues
Revenues	$ 44	$ 0	$ 100	$ 0