CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 137	$ 188	$ 669	$ (1,088)
Net change in unrealized gains (losses), net of tax:
Investment securities	(86)	56	(664)	924
Fair value option liabilities attributable to our own credit spread	9	(40)	9	106
Derivatives designated as cash flow hedges	(7)	(10)	(28)	83
Pension and post-retirement benefit plans	0	(2)	1	(2)
Total other comprehensive income (loss)	(84)	4	(682)	1,111
Comprehensive income (loss)	$ 53	$ 192	$ (13)	$ 23