Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 373	$ 199	$ 171
Securities available for sale:
Unrealized (losses) gains arising during the period, net of tax (benefit) expense of $5, $3 and $7	(17)	(6)	(14)
Reclassification adjustment for gains included in net income, net of tax expense of $0, $0 and $0	0	0	0
Derivative instruments:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(1), $0 and $3	(2)	(1)	5
Reclassification adjustment for (gains) losses included in net income, net of tax expense (benefit) of $0, $0 and $1	(2)	0	(1)
Pension and postretirement benefit obligations:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $1, $0 and $0	(2)	0	0
Other Comprehensive (Loss) Income	(23)	(7)	(10)
Comprehensive Income	$ 350	$ 192	$ 161