Accumulated Other Comprehensive Income - Reclassifications Out of AOCI (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income	[1]	$ 147	$ 15	$ 68
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		3,281	1,585	2,054
Income taxes		642	227	314
Interest income — Loans		3,532	3,866	4,267
Interest expense — Long-term debt		(221)	(286)	(454)
Investment banking and debt placement fees		937	661	630
Other expense		2,561	2,336	2,250
Income (loss) from continuing operations		2,612	1,329	$ 1,708
Reclassification out of Accumulated Other Comprehensive Income | Unrealized gains (losses) on securities available for sale
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income		7	4
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		7	4
Income taxes		2	1
Income (loss) from continuing operations		5	3
Reclassification out of Accumulated Other Comprehensive Income | Unrealized gains (losses) on derivative financial instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		329	315
Income taxes		78	75
Income (loss) from continuing operations		251	240
Reclassification out of Accumulated Other Comprehensive Income | Unrealized gains (losses) on derivative financial instruments | Interest rate
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income — Loans		329	319
Interest expense — Long-term debt		(4)	(4)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized gains (losses) on derivative financial instruments | Interest rate | Investment banking and debt placement fees
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment banking and debt placement fees		4	0
Reclassification out of Accumulated Other Comprehensive Income | Net pension and postretirement benefit costs
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		(26)	(25)
Income taxes		(6)	(6)
Income (loss) from continuing operations		(20)	(19)
Reclassification out of Accumulated Other Comprehensive Income | Net pension and postretirement benefit costs | Amortization of losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense		(18)	(17)
Reclassification out of Accumulated Other Comprehensive Income | Net pension and postretirement benefit costs | Settlement loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense		(9)	(9)
Reclassification out of Accumulated Other Comprehensive Income | Net pension and postretirement benefit costs | Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense		$ 1	$ 1

[1] Net securities gains (losses) totaled $7 million for the year ended December 31, 2021, $4 million for the year ended December 31, 2020, and $20 million for the year ended December 31, 2019. For 2021, 2020, and 2019, we did not have any impairment losses related to securities.