Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income for the period	$ 213	$ 238
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on investment securities	122	(126)
Net unrealized gains (losses) on other noninterest-bearing investments	(3)	1
Net unrealized holding gains (losses) on derivative instruments	8	(3)
Reclassification adjustment for decrease in interest income recognized in earnings on derivatives instruments	1	0
Other comprehensive income (loss)	128	(128)
Comprehensive income	$ 341	$ 110