Organization (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	$ 14,597,758,000	$ 13,950,312,000	$ 13,015,188,000
Farm & Ranch [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	5,417,174,000	5,163,080,000	4,747,289,000
USDA Guarantees [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	1,798,034,000	1,687,117,000	1,615,579,000
Rural Utilities [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	985,609,000	1,052,251,000	1,031,945,000
Institutional Credit [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	6,396,941,000	6,047,864,000	5,620,375,000
Medium-term Notes [Member]
Product Information [Line Items]
Notes Payable	7,900,000,000
Discount Notes [Member]
Product Information [Line Items]
Notes Payable	$ 4,900,000,000