CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 84	$ 95	$ 131	$ 189
Securities available for sale:
Unrealized gains arising during the period, net of tax expense of $4 and $9, $19 and $16	13	30	66	54
Derivative instruments:
Unrealized losses arising during the period, net of tax benefit of $(1) and $(4), $(11) and $(6)	(5)	(14)	(40)	(20)
Reclassification adjustment for gains included in net income, net of tax expense of $(1) and $0, $(1) and $0	2	0	3	(1)
Pension and postretirement benefit obligations:
Unrealized gains arising during the period, net of tax expense of $0 and $0, $0 and $0	0	0	1	1
Other Comprehensive Income	10	16	30	34
Comprehensive Income	$ 94	$ 111	$ 161	$ 223