Consolidated Statements of Comprehensive Income Consolidated Statement of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax	$ 51	$ (55)	$ 294	$ (223)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	25	(6)	93	(55)
Other Comprehensive Income (Loss), Brokered Time Deposits, Tax	0	0	0	0
Other Comprehensive Income (Loss), Long Term Debt, Adjustment, Tax	0	0	0	1
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	$ 1	$ 1	$ 4	$ 1