Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Restricted cash (includes $33,294 and $17,849, respectively, related to consolidated trusts)	$ 40,223	$ 23,866
Investments in securities:
Available-for-sale, at fair value	2,404	3,429
Mortgage loans:
Loans held for investment, at amortized cost of consolidated trusts (includes $12,057 and $14,075, respectively, at fair value)	7,825	8,922
Accrued interest receivable, net (includes $8,172 and $7,928, respectively, related to consolidated trusts)	8,604	8,490
Liabilities:
Accrued interest payable (includes $9,361 and $9,133, respectively, related to consolidated trusts)	10,228	10,211
Other liabilities (includes $376 and $356, respectively, related to consolidated trusts)	$ 11,097	$ 9,947
Fannie Mae stockholders’ equity:
Senior preferred stock, 1,000,000 shares outstanding	131,178	123,836
Preferred stock, 700,000,000 shares are authorized	700,000,000	700,000,000
Preferred stock, 555,374,922 shares issued	555,374,922	555,374,922
Preferred stock, 555,374,922 shares outstanding	555,374,922	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, no par value, no maximum authorization, 1,158,087,567 and 1,158,082,750 shares outstanding, respectively	1,200,000,000	1,158,087,567
Treasury stock, at cost, 150,675,136 and 150,679,953 shares, respectively	150,675,136	150,675,136
Security Owned and Pledged as Collateral, Fair Value	$ 0	$ 0
Consolidated Trusts [Member]
ASSETS
Restricted cash (includes $33,294 and $17,849, respectively, related to consolidated trusts)	33,294	17,849
Mortgage loans:
Accrued interest receivable, net (includes $8,172 and $7,928, respectively, related to consolidated trusts)	8,172	7,928
Liabilities:
Accrued interest payable (includes $9,361 and $9,133, respectively, related to consolidated trusts)	9,361	9,133
Debt at fair value	21,880	23,753
Other liabilities (includes $376 and $356, respectively, related to consolidated trusts)	376	356
Fannie Mae [Member]
Liabilities:
Debt at fair value	$ 5,687	$ 6,826

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