CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 93	$ 47
Securities available for sale:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(6) and $15	(21)	53
Derivative instruments:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $1 and $(10)	4	(35)
Reclassification adjustment for gains (losses) included in net income, net of tax expense (benefit) of $1 and $0	4	1
Pension and postretirement benefit obligations:
Unrealized gains arising during the period, net of tax expense of $0 and $0	1	1
Other Comprehensive Income (Loss)	(12)	20
Comprehensive Income	$ 81	$ 67