CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net Income	$ 704	$ 581	$ 2,107	$ 823
Unrealized gains on available-for-sale debt securities:
Unrealized holding (losses) gains arising during period	(281)	(32)	(748)	1,306
Reclassification adjustment for net losses (gains) included in net income	(1)	(34)	7	(34)
Unrealized gains on cash flow hedge derivatives:
Unrealized holding (losses) gains arising during period	2	1	(53)	494
Reclassification adjustment for net gains included in net income	(58)	(56)	(173)	(130)
Defined benefit pension plans, net:
Net actuarial loss arising during the year	(1)	(2)	(2)	(2)
Reclassification of amounts to net periodic benefit costs	2	3	5	5
Other comprehensive (loss) income, net of tax	(337)	(120)	(964)	1,639
Comprehensive Income	$ 367	$ 461	$ 1,143	$ 2,462