CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 188	$ (250)	$ (1,088)	$ (20)
Net change in unrealized gains (losses), net of tax:
Investment securities	56	86	924	485
Fair value option liabilities attributable to our own credit spread	(40)	(3)	106	(107)
Derivatives designated as cash flow hedges	(10)	(10)	83	9
Pension and post-retirement benefit plans	(2)	(1)	(2)	(4)
Total other comprehensive income	4	72	1,111	383
Comprehensive income (loss)	$ 192	$ (178)	$ 23	$ 363