Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Assets pledged	$ 166,600	$ 125,200
Available-for-sale securities, amortized cost	381,729	345,306
Held-to-maturity securities, allowance for credit losses	78
Loans	$ 44,474	$ 44,955
Stockholders’ equity
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	200,000,000	200,000,000
Preferred stock, shares issued (in shares)	3,006,250	2,699,250
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	9,000,000,000.0	9,000,000,000
Common stock, shares issued (in shares)	4,104,933,895	4,104,933,895
Shares held in Trust, shares (in shares)	0	472,953
Treasury stock, shares (in shares)	1,055,499,435	1,020,912,567
Trading assets
Assets
Assets pledged	$ 130,645	$ 111,522
Investment securities - AFS
Assets
Assets pledged	32,227	10,325
Other assets
Assets
Assets pledged	3,739	3,349
Recurring
Assets
Federal funds sold and securities purchased under resale agreements	238,015	14,561
Securities borrowed	52,983	6,237
Loans	44,474	44,955
Liabilities
Deposits	14,484	28,589
Federal funds purchased and securities loaned or sold under repurchase agreements	155,735	549
Short-term borrowings	16,893	5,920
Accounts payable and other liabilities	3,476	3,728
Beneficial interests issued by consolidated VIEs	41	36
Long-term debt	76,817	75,745
Recurring | Other assets
Assets
Other assets	$ 13,827	$ 12,676