Condensed Financial Information (Parent Only) (Details - Condensed Statement of Comprehensive Income) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Other revenue									$ 48	$ 45	$ 43
Total net revenue	$ 679	$ 767	$ 685	$ 755	$ 735	$ 720	$ 710	$ 708	2,886	2,873	2,366
Total non-interest expense									1,618	1,541	1,470
Income before income tax expense (benefit) and equity in income (loss) of consolidated subsidiaries									1,319	1,418	1,064
Income tax expense (benefit)									364	366	450
Net income	$ 172	$ 274	$ 219	$ 290	$ 270	$ 285	$ 250	$ 247	955	1,052	614
Other comprehensive (loss) income									247	(228)	111
Comprehensive income									1,202	824	725
Net income available to common shareholders									915	1,016	589
Preferred stock dividends									40	36	25
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from subsidiaries(1)									1,770	1,150	350
Other revenue									404	410	377
Total net revenue									2,174	1,560	727
Total non-interest expense									603	575	611
Income before income tax expense (benefit) and equity in income (loss) of consolidated subsidiaries									1,571	985	116
Income tax expense (benefit)									184	149	75
Equity in undistributed income (loss) of subsidiaries									(432)	216	573
Net income									955	1,052	614
Other comprehensive (loss) income									247	(228)	111
Comprehensive income									1,202	824	725
Net income available to common shareholders									915	1,000	589
Preferred stock dividends									$ 40	$ 36	$ 25