Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 907	$ 1,129	$ 539
Other comprehensive income (loss), net of tax:
Net unrealized holding gains (losses) on investment securities	(2,722)	(336)	229
Net unrealized gains (losses) on other noninterest-bearing investments	(2)	3	1
Net unrealized holding gains (losses) on derivative instruments	(330)	(26)	76
Reclassification adjustment for decrease (increase) in interest income recognized in earnings on derivative instruments	21	(46)	(36)
Pension and post-retirement	1	0	12
Other comprehensive income (loss), net of tax	(3,032)	(405)	282
Comprehensive income (loss)	$ (2,125)	$ 724	$ 821