Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 405	$ 286	$ 387
Securities available for sale:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(16), $15 and $16	(57)	54	57
Derivative instruments:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $1, $(11) and $(5)	4	(40)	(17)
Reclassification adjustment for gains (losses) included in net income, net of tax expense (benefit) of $4, $3 and $0	14	18	(2)
Pension and postretirement benefit obligations:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(5), $2 and $(1)	16	(6)	3
Other Comprehensive Income (Loss)	(23)	26	41
Comprehensive Income	$ 382	$ 312	$ 428