Parent Company Financial Statements - Condensed Balance Sheet - Parent Company Only (Details) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash		$ 2,994	$ 3,147	$ 3,278	$ 2,681
Equity securities		376	313
Goodwill		4,514	4,258	4,252
Other assets	[1]	11,444	10,749
Total Assets		211,116	204,680
Liabilities
Other short-term borrowings		980	1,192
Accrued expenses and other liabilities	[1]	4,267	3,409
Long-term debt (external)	[1]	11,821	14,973
Total Liabilities		188,906	181,569
Equity
Common stock	[2]	2,051	2,051
Preferred stock	[3]	2,116	2,116
Capital surplus		3,624	3,635
Retained earnings		20,236	18,384
Accumulated other comprehensive income		1,207	2,601
Treasury stock	[2]	(7,024)	(5,676)
Total Equity		22,210	23,111	21,203	16,250
Total Liabilities and Equity		211,116	204,680
Parent Company
Assets
Cash		122	120	$ 118	$ 120
Other short-term investments		6,234	5,578
Equity securities		49	49
Loans to nonbank subsidiaries		192	350
Investment in nonbank subsidiaries		23,877	25,214
Goodwill		80	80
Other assets		431	479
Total Assets		30,985	31,870
Liabilities
Other short-term borrowings		361	450
Accrued expenses and other liabilities		487	548
Long-term debt (external)		7,927	7,761
Total Liabilities		8,775	8,759
Equity
Common stock		2,051	2,051
Preferred stock		2,116	2,116
Capital surplus		3,624	3,635
Retained earnings		20,236	18,384
Accumulated other comprehensive income		1,207	2,601
Treasury stock		(7,024)	(5,676)
Total Equity		22,210	23,111
Total Liabilities and Equity		$ 30,985	$ 31,870

[1] Includes $24 and $55 of other short-term investments, $322 and $756 of portfolio loans and leases, $(2) and $(7) of ALLL, $2 and $5 of other assets, $1 and $2 of other liabilities and $263 and $656 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2021 and 2020, respectively. For further information, refer to Note 12.

[2] Common shares: Stated value $2.22 per share; authorized 2,000,000,000; outstanding at December 31, 2021 – 682,777,664 (excludes 241,114,917 treasury shares), 2020 – 712,760,325 (excludes 211,132,256 treasury shares).

[3] 500,000 shares of no par value preferred stock were authorized at both December 31, 2021 and 2020. There were 422,000 unissued shares of undesignated no par value preferred stock at both December 31, 2021 and 2020. 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, 2021 and 2020. There were 300,000 unissued shares of undesignated no par value Class B preferred stock at both December 31, 2021 and 2020. Each issued share of no par value Class B preferred stock has a liquidation preference of $1,000.