Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 24,728		$ 17,539
Restricted cash (includes $51,205 and $45,900, respectively, related to consolidated trusts)	55,985		50,797
Federal funds sold and securities purchased under agreements to resell or similar arrangements	24,000		46,000
Investments in securities:
Trading, at fair value	50,935		74,198
Available-for-sale, at fair value (includes $998 and $1,191, respectively, related to consolidated trusts)	69,694		77,582
Total investments in securities	120,629		151,780
Mortgage loans:
Loans held for sale, at lower of cost or fair value (includes $72 and $66, respectively, related to consolidated trusts)	455		311
Loans held for investment, at amortized cost (includes $5,231 and $3,611, respectively, at fair value and loans pledged as collateral that may be sold or repledged of $1,126 and $798, respectively, related to consolidated trusts)	2,986,162		2,970,466
Allowance for loan losses	(63,375)	[1]	(72,156)
Total loans held for investment, net of allowance	2,922,787		2,898,310
Total mortgage loans	2,923,242		2,898,621
Accrued interest receivable, net (includes $8,107 and $8,466, respectively, related to consolidated trusts)	9,668		10,000
Acquired property, net	10,387		11,373
Other assets (includes cash pledged as collateral of $1,535 and $1,109, respectively)	26,981		25,374
Total assets	3,195,620		3,211,484
Liabilities:
Accrued interest payable (includes $9,018 and $9,302, respectively, related to consolidated trusts)	11,858		12,648
Federal funds purchased and securities sold under agreements to repurchase	153	[2]	0	[2]
Other liabilities (includes $762 and $629, respectively, related to consolidated trusts)	16,951		13,535
Total liabilities	3,192,850		3,216,055
Commitments and contingencies (Note 13)
Fannie Mae stockholders' equity (deficit):
Senior preferred stock, 1,000,000 shares issued and outstanding	117,149		112,578
Preferred stock, 700,000,000 shares are authorized—555,374,922 shares issued and outstanding	19,130		19,130
Common stock, no par value, no maximum authorization— 1,308,762,703 shares issued, 1,158,069,699 and 1,157,767,400 shares outstanding, respectively	687		687
Accumulated deficit	(126,300)		(128,381)
Accumulated other comprehensive loss	(545)		(1,235)
Treasury stock, at cost, 150,693,004 and 150,995,303 shares, respectively	(7,401)		(7,403)
Total Fannie Mae stockholders' equity (deficit)	2,720		(4,624)
Noncontrolling interest	50		53
Total equity (deficit)	2,770		(4,571)
Total liabilities and equity (deficit)	3,195,620		3,211,484
Fannie Mae [Member]
Mortgage loans:
Loans held for investment, at amortized cost (includes $5,231 and $3,611, respectively, at fair value and loans pledged as collateral that may be sold or repledged of $1,126 and $798, respectively, related to consolidated trusts)	369,660		380,134
Allowance for loan losses	(52,082)		(57,309)
Total mortgage loans	317,961		323,070
Liabilities:
Debt (includes $831 and $838, respectively, of debt of Fannie Mae and $4,600 and $3,939, respectively, of debt of consolidated trusts, at fair value)	659,389		732,444
Consolidated Trusts [Member]
ASSETS
Restricted cash (includes $51,205 and $45,900, respectively, related to consolidated trusts)	51,205		45,900
Investments in securities:
Available-for-sale, at fair value (includes $998 and $1,191, respectively, related to consolidated trusts)	998		1,191
Mortgage loans:
Loans held for sale, at lower of cost or fair value (includes $72 and $66, respectively, related to consolidated trusts)	72		66
Loans held for investment, at amortized cost (includes $5,231 and $3,611, respectively, at fair value and loans pledged as collateral that may be sold or repledged of $1,126 and $798, respectively, related to consolidated trusts)	2,616,502		2,590,332
Allowance for loan losses	(11,293)		(14,847)
Total mortgage loans	2,605,281		2,575,551
Accrued interest receivable, net (includes $8,107 and $8,466, respectively, related to consolidated trusts)	8,107		8,466
Liabilities:
Accrued interest payable (includes $9,018 and $9,302, respectively, related to consolidated trusts)	9,018		9,302
Debt (includes $831 and $838, respectively, of debt of Fannie Mae and $4,600 and $3,939, respectively, of debt of consolidated trusts, at fair value)	2,504,499		2,457,428
Other liabilities (includes $762 and $629, respectively, related to consolidated trusts)	$ 762		$ 629

[1] Total allowance for loan losses includes $293 million and $414 million as of June 30, 2012 and 2011, respectively, for acquired credit-impaired loans.

[2] Represents agreements to repurchase securities for a specified price, with repayment generally occurring on the following day.