Organization - Organization (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	$ 15,898,820	$ 14,597,758	$ 13,950,312
Medium-term Notes [Member]
Product Information [Line Items]
Notes Payable	7,400,000
Farm & Ranch [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	5,725,299	5,417,174	5,163,080
USDA Guarantees [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	1,918,277	1,798,034	1,687,117
Rural Utilities [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	1,530,990	985,609	1,052,251
Institutional Credit [Member]
Product Information [Line Items]
On and Off Balance Sheet Program Assets, At Principal Balance	6,724,254	$ 6,396,941	$ 6,047,864
Discount Notes [Member]
Product Information [Line Items]
Notes Payable	$ 6,600,000