Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	[1]	Sep. 30, 2020	Sep. 30, 2019	[1]
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (401)	$ 1,187		$ (693)	$ 3,514
Other comprehensive income (loss), net of tax:
Change in value of available-for-sale securities	3	0		3	8
Actuarial gain (loss) related to pension and other postretirement benefit plans	4	(3)		15	7
Foreign currency translation adjustments	18	0		(16)	0
Change in other comprehensive income (loss) from unconsolidated affiliates	1	(4)		(15)	(13)
Other comprehensive income (loss), net of tax	26	(7)		(13)	2
Comprehensive income (loss)	(375)	1,180		(706)	3,516
Less: Comprehensive income attributable to noncontrolling interests	369	317		554	931
Less: Net income attributable to redeemable noncontrolling interests	12	12		37	38
Comprehensive income (loss) attributable to partners	$ (756)	$ 851		$ (1,297)	$ 2,547

[1] *As adjusted. See Note 1.