Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net income for the period	$ 139	$ 91
Other comprehensive income, net of tax:
Unrealized holding gains on investment securities	12	32
Net unrealized gains on other noninterest-bearing investments	1	1
Net unrealized holding gains (losses) on derivative instruments	(1)	13
Reclassification adjustment for increase in interest income recognized in earnings on derivatives instruments	(1)	(2)
Pension and Postretirement	0	(1)
Other comprehensive income	11	43
Comprehensive income	$ 150	$ 134