Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net income for the period	$ 198	$ 197	$ 411	$ 435
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on investment securities	116	(50)	237	(175)
Net unrealized gains (losses) on other noninterest-bearing investments	0	2	(3)	3
Net unrealized holding gains (losses) on derivative instruments	31	(2)	39	(5)
Reclassification adjustment for decrease in interest income recognized in earnings on derivatives instruments	1	1	2	1
Other comprehensive income (loss)	148	(49)	275	(176)
Comprehensive income	$ 346	$ 148	$ 686	$ 259