CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net Income	$ 709	$ 195	$ 1,403	$ 243
Unrealized gains on available-for-sale debt securities:
Unrealized holding (losses) gains arising during period	235	456	(466)	1,338
Reclassification adjustment for net losses (gains) included in net income	(5)	0	7	0
Unrealized gains on cash flow hedge derivatives:
Unrealized holding (losses) gains arising during period	9	66	(55)	493
Reclassification adjustment for net gains included in net income	(58)	(49)	(115)	(74)
Defined benefit pension plans, net:
Net actuarial loss arising during the year	(1)	0	(1)	0
Reclassification of amounts to net periodic benefit costs	2	1	3	2
Other comprehensive (loss) income, net of tax	182	474	(627)	1,759
Comprehensive Income	$ 891	$ 669	$ 776	$ 2,002