Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents (includes $68,308 and $33,294, respectively, related to consolidated trusts)	$ 77,286	$ 40,223
Security Owned and Pledged as Collateral, Fair Value	6,544	3,037
Debt Securities, Available-for-sale, Allowance for Credit Loss	1,606	2,281
Debt Securities, Available-for-sale, Allowance for Credit Loss	3
Loans held for investment, at amortized cost of consolidated trusts (includes $12,057 and $14,075, respectively, at fair value)	6,490	7,825
Interest Receivable	9,937	8,604
Interest Payable	9,719	10,228
Other Liabilities	$ 15,035	$ 11,097
Senior preferred stock, 1,000,000 shares outstanding	142,192,000,000	131,178,000,000
Preferred stock, 700,000,000 shares are authorized	700,000,000	700,000,000
Preferred stock, shares outstanding	555,374,922	555,374,922
Preferred stock, 555,374,922 shares issued	555,374,922
Common stock, no par value, no maximum authorization, 1,308,762,703 shares issued	1,308,762,703	1,308,762,703
Common Stock, Shares, Outstanding	1,158,087,567	1,158,087,567
Treasury stock, at cost, 150,675,136 and 150,679,953 shares, respectively	150,675,136	150,675,136
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member]
Interest Receivable	$ 216
Consolidated Trusts [Member]
Restricted Cash and Cash Equivalents (includes $68,308 and $33,294, respectively, related to consolidated trusts)	68,308	$ 33,294
Interest Receivable	9,635	8,172
Interest Payable	8,955	9,361
Long-term debt	24,586	21,880
Other Liabilities	1,523	376
Fannie Mae [Member]
Long-term debt	$ 3,728	$ 5,687