Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows used in operating activities:
Net cash provided by (used in) operating activities	$ 32,279	$ (6,714)
Cash flows provided by investing activities:
Purchases of trading securities held for investment	(1,542)	(2,483)
Proceeds from maturities and paydowns of trading securities held for investment	2,671	1,672
Proceeds from sales of trading securities held for investment	1,357	837
Purchases of available-for-sale securities	(34)	(44)
Proceeds from maturities and paydowns of available-for-sale securities	9,423	9,995
Proceeds from sales of available-for-sale securities	923	2,590
Purchases of loans held for investment	(141,539)	(44,276)
Net change in restricted cash	(9,147)	7,717
Advances to lenders	(97,508)	(43,363)
Proceeds from disposition of acquired property and preforeclosure sales	29,822	36,280
Net change in federal funds sold and securities purchased under agreements to resell or similar agreements	500	(24,199)
Other, net	56	137
Net cash provided by investing activities	386,403	327,830
Cash flows used in financing activities:
Payments of cash dividends on senior preferred stock to Treasury	(8,679)	(6,992)
Proceeds from senior preferred stock purchase agreement with Treasury	4,571	16,187
Other, net	(9)	150
Net cash used in financing activities	(415,547)	(314,106)
Net increase (decrease) in cash and cash equivalents	3,135	7,010
Cash and cash equivalents at beginning of period	17,539	17,297
Cash and cash equivalents at end of period	20,674	24,307
Cash paid during the period for:
Cash paid during the period for interest	90,338	97,592
Fannie Mae [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans held for investment	22,540	18,467
Cash flows used in financing activities:
Proceeds from the issuance of debt	550,087	572,828
Payments to redeem debt	(630,546)	(609,399)
Consolidated Trusts [Member]
Cash flows provided by investing activities:
Proceeds from repayments of loans held for investment	568,881	364,500
Cash flows used in financing activities:
Proceeds from the issuance of debt	270,552	157,280
Payments to redeem debt	$ (601,523)	$ (444,160)