Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Member’s Equity	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2018	$ 42,649	$ 42,519	$ 130
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(1,200)	(1,200)	0
Comprehensive income (loss), net of tax	1,315	1,253	62
Ending Balance at Mar. 31, 2019	42,764	42,572	192
Beginning Balance at Dec. 31, 2018	42,649	42,519	130
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(3,400)
Comprehensive income (loss), net of tax	4,119
Ending Balance at Sep. 30, 2019	43,368	43,176	192
Beginning Balance at Mar. 31, 2019	42,764	42,572	192
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(1,200)	(1,200)	0
Comprehensive income (loss), net of tax	1,338	1,338	0
Ending Balance at Jun. 30, 2019	42,902	42,710	192
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(1,000)	(1,000)	0
Comprehensive income (loss), net of tax	1,466	1,466	0
Ending Balance at Sep. 30, 2019	43,368	43,176	192
Beginning Balance at Dec. 31, 2019	43,720	43,575	145
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(1,100)	(1,100)	0
Comprehensive income (loss), net of tax	1,191	1,190	1
Ending Balance at Mar. 31, 2020	43,811	43,665	146
Beginning Balance at Dec. 31, 2019	43,720	43,575	145
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(3,100)
Comprehensive income (loss), net of tax	3,670
Ending Balance at Sep. 30, 2020	44,290	44,143	147
Beginning Balance at Mar. 31, 2020	43,811	43,665	146
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(1,300)	(1,300)	0
Comprehensive income (loss), net of tax	1,132	1,131	1
Ending Balance at Jun. 30, 2020	43,643	43,496	147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash distributions	(700)	(700)	0
Comprehensive income (loss), net of tax	1,347	1,347	0
Ending Balance at Sep. 30, 2020	$ 44,290	$ 44,143	$ 147