Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Restricted cash (includes $22,132 and $31,536, respectively, related to consolidated trusts)	$ 28,150	$ 36,953
Investments in securities:
Trading, at fair value (includes $747 and $1,277, respectively, pledged as collateral)	747	1,277
Available-for-sale, at fair value (includes $87 and $107, respectively, related to consolidated trusts)	4,843	8,363
Mortgage loans:
Loans held for investment, at amortized cost of consolidated trusts (includes $12,057 and $14,075, respectively, at fair value)	10,596	12,057
Accrued interest receivable, net (includes $7,560 and $7,064, respectively, related to consolidated trusts)	8,133	7,737
Liabilities:
Accrued interest payable (includes $8,598 and $8,285, respectively, related to consolidated trusts)	9,682	9,431
Other liabilities (includes $492 and $390, respectively, related to consolidated trusts)	$ 9,479	$ 10,150
Fannie Mae stockholders’ equity (deficit):
Senior preferred stock, 1,000,000 shares issued	1,000,000	1,000,000
Senior preferred stock, 1,000,000 shares outstanding	1,000,000	1,000,000
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	1,158,087,567	1,158,082,750
Treasury stock, at cost, 150,675,136 and 150,679,953 shares, respectively	150,675,136	150,679,953
Consolidated Trusts [Member]
ASSETS
Restricted cash (includes $22,132 and $31,536, respectively, related to consolidated trusts)	$ 22,132	$ 31,536
Investments in securities:
Available-for-sale, at fair value (includes $87 and $107, respectively, related to consolidated trusts)	87	107
Mortgage loans:
Accrued interest receivable, net (includes $7,560 and $7,064, respectively, related to consolidated trusts)	7,560	7,064
Liabilities:
Accrued interest payable (includes $8,598 and $8,285, respectively, related to consolidated trusts)	8,598	8,285
Debt at fair value	30,493	36,524
Other liabilities (includes $492 and $390, respectively, related to consolidated trusts)	492	390
Fannie Mae [Member]
Liabilities:
Debt at fair value	$ 8,186	$ 9,582