Consolidated Statements Of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statements of Comprehensive Income (Loss)
Net income (loss)	$ (61)	$ (106)	$ (167)	$ (439)
Available-for-sale securities with no credit losses:
Unrealized gains (losses) arising during the period	55	40	(32)	88
Reclassification adjustments for (gains) losses included in net income (loss)	(3)	(5)	(8)	(8)
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	6	3	1	49
Reclassification adjustments for (gains) losses included in net income (loss)	4	1	24	3
Total other comprehensive income (loss)	64	38	(12)	131
Comprehensive income (loss)	$ 3	$ (68)	$ (179)	$ (308)