Consolidated Statements Of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statements of Comprehensive Income (Loss)
Net income (loss)	$ (58)	$ 83	$ (497)	$ (145)
Available-for-sale securities with no credit losses:
Unrealized gains (losses) arising during the period	5	39	93	164
Provision (benefit) for income taxes	0	1	0	0
Total	5	38	93	164
Reclassification adjustments for (gains) losses included in net income (loss)	(9)	8	(17)	(15)
Available-for-sale securities with credit losses:
Unrealized gains (losses) arising during the period	0	(32)	0	(2)
Reclassification adjustments for (gains) losses included in net income (loss)	0	(42)	0	(5)
Foreign currency translation:
Foreign currency translation gains (losses)	(2)	1	(3)	1
Instrument-specific credit risk of liabilities measured at fair value:
Unrealized gains (losses) arising during the period	5	(27)	54	(27)
Reclassification adjustments for (gains) losses included in net income (loss)	2	3	5	26
Total other comprehensive income (loss)	1	(51)	132	142
Comprehensive income (loss)	$ (57)	$ 32	$ (365)	$ (3)