CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 485	$ 439	$ 405
Securities available for sale:
Unrealized (losses) gains arising during the period, net of tax (benefit) expense of $16, $(79) and $(16)	57	(277)	(57)
Reclassification adjustment for losses included in net income, net of tax (benefit) expense of $(15), $0 and $0	52	0	0
Derivative instruments:
Unrealized (losses) gains arising during the period, net of tax (benefit) expense of $(2), $(9) and $1	(8)	(30)	4
Reclassification adjustment for gains (losses) included in net income, net of tax expense (benefit) of $5, $2 and $4	19	8	14
Pension and postretirement benefit obligations:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(1), $(1) and $(5)	2	4	16
Other Comprehensive Income (Loss)	122	(295)	(23)
Comprehensive Income (Loss)	$ 607	$ 144	$ 382