Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Trading securities	$ 706	$ 516	$ 444
Available-for-sale securities	335	620	1,156
Mortgage loans (includes $100,593, $95,266 and $97,971, respectively, related to consolidated trusts)	108,319	104,642	107,699
Other	496	243	143
Total interest income	109,856	106,021	109,442
Interest expense:
Short-term debt	(250)	(206)	(146)
Long-term debt (includes $82,580, $77,575 and $80,326, respectively, related to consolidated trusts)	(88,873)	(84,520)	(87,887)
Total interest expense	(89,123)	(84,726)	(88,033)
Net interest income	20,733	21,295	21,409
Benefit for credit losses	2,041	2,155	795
Net interest income after benefit for credit losses	22,774	23,450	22,204
Non-interest Income:
Investment gains, net	1,522	1,256	1,336
Fair value losses, net	(1,211)	(1,081)	(1,767)
Fee and other income	2,227	966	1,348
Non-interest income	2,538	1,141	917
Administrative expenses:
Salaries and employee benefits	(1,328)	(1,336)	(1,319)
Professional services	(933)	(955)	(984)
Other administrative expenses	(476)	(450)	(747)
Total administrative expenses	(2,737)	(2,741)	(3,050)
Foreclosed property expense	(521)	(644)	(1,629)
Temporary Payroll Cut Continuation Act of 2011 (“TCCA”) fees	(2,096)	(1,845)	(1,621)
Other expenses, net	(1,511)	(1,028)	(613)
Total expenses	(6,865)	(6,258)	(6,913)
Income before federal income taxes	18,447	18,333	16,208
Provision for federal income taxes	(15,984)	(6,020)	(5,253)
Net income	2,463	12,313	10,955
Total comprehensive income
Changes in unrealized gains on available-for-sale securities, net of reclassification adjustments and taxes	(206)	(642)	(763)
Other	0	(6)	(437)
Total other comprehensive loss	(206)	(648)	(326)
Total comprehensive income	2,257	11,665	10,629
Less: Comprehensive income attributable to noncontrolling interest	0	0	(1)
Total comprehensive income attributable to Fannie Mae	2,257	11,665	10,628
Less: Net income attributable to noncontrolling interest	0	0	(1)
Net income attributable to Fannie Mae	2,463	12,313	10,954
Dividends distributed or available for distribution to senior preferred stockholder	(8,944)	(12,236)	(11,216)
Net income (loss) attributable to common stockholders	$ (6,481)	$ 77	$ (262)
Earnings (loss) per share: Basic	$ (1.12)	$ 0.01	$ (0.05)
Earnings (loss) per share: Diluted	$ (1.12)	$ 0.01	$ (0.05)
Weighted-average common shares outstanding: Basic	5,762	5,762	5,762
Weighted-average common shares outstanding: Diluted	5,762	5,893	5,762