Parent Company Financial Statements - Condensed Balance Sheet - Parent Company Only (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Other short-term investments	[1]	$ 22,082	$ 8,351
Available-for-sale debt and other securities	[2]	50,419	51,503
Equity securities		613	317
Goodwill		4,919	4,915	$ 4,514
Other assets	[1]	12,538	13,459
Total Assets		214,574	207,452
Liabilities
Other short-term borrowings		2,861	4,838
Accrued expenses and other liabilities	[1]	4,861	5,881
Long-term debt (external)	[1]	16,380	13,714
Total Liabilities		195,402	190,125
Equity
Common stock	[3]	2,051	2,051
Preferred stock	[4]	2,116	2,116
Capital surplus		3,757	3,684
Retained earnings		22,997	21,689
Accumulated other comprehensive loss		(4,487)	(5,110)
Treasury stock	[3]	(7,262)	(7,103)
Total Equity		19,172	17,327	22,210	$ 23,111
Total Liabilities and Equity		214,574	207,452
Parent Company
Assets
Cash		120	120	$ 122	$ 120
Other short-term investments		6,500	5,667
Available-for-sale debt and other securities		1,000	1,000
Equity securities		34	34
Loans to nonbank subsidiaries		0	60
Investment in nonbank subsidiaries		21,998	20,256
Goodwill		80	80
Other assets		179	326
Total Assets		29,911	27,543
Liabilities
Other short-term borrowings		0	121
Accrued expenses and other liabilities		631	764
Long-term debt (external)		10,108	9,331
Total Liabilities		10,739	10,216
Equity
Common stock		2,051	2,051
Preferred stock		2,116	2,116
Capital surplus		3,757	3,684
Retained earnings		22,997	21,689
Accumulated other comprehensive loss		(4,487)	(5,110)
Treasury stock		(7,262)	(7,103)
Total Equity		19,172	17,327
Total Liabilities and Equity		$ 29,911	$ 27,543

[1] Includes $55 and $17 of other short-term investments, $1,573 and $185 of portfolio loans and leases, $(28) and $(2) of ALLL, $10 and $2 of other assets, $14 and $9 of other liabilities and $1,409 and $118 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2023 and 2022, respectively. For further information, refer to Note 12.

[2] Amortized cost of $55,789 and $57,530 at December 31, 2023 and 2022, respectively.

[3] Common shares: Stated value $2.22 per share; authorized 2,000,000,000; outstanding at December 31, 2023 – 681,124,810 (excludes 242,767,771 treasury shares), 2022 – 683,385,880 (excludes 240,506,701 treasury shares).

[4] 500,000 shares of no par value preferred stock were authorized at both December 31, 2023 and 2022. There were 422,000 unissued shares of undesignated no par value preferred stock at both December 31, 2023 and 2022. Each issued share of no par value preferred stock has a liquidation preference of $25,000. 500,000 shares of no par value Class B preferred stock were authorized at both December 31, 2023 and 2022. There were 300,000 unissued shares of undesignated no par value Class B preferred stock at both December 31, 2023 and 2022. Each issued share of no par value Class B preferred stock has a liquidation preference of $1,000.