CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income for the period	$ 201	$ 175	$ 354	$ 379
Other comprehensive income (loss), net of tax:
Net unrealized holding gains (losses) on investment securities	(14)	(86)	(2)	(9)
Unrealized loss amortization associated with the securities transferred from AFS to HTM	50	54	96	103
Net unrealized gains on other noninterest-bearing investments	1	0	1	0
Net unrealized holding gains (losses) on derivative instruments	0	(8)	(1)	21
Reclassification adjustment for decrease in interest income recognized in earnings on derivative instruments	23	30	49	67
Other comprehensive income (loss), net of tax	60	(10)	143	182
Comprehensive income	$ 261	$ 165	$ 497	$ 561