Farmer Mac Guaranteed Securities and USDA Securities - Schedule of Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
AgVantage
Weighted- Average Yield
Held-to-maturity, accrued interest excluded	$ 34,500	$ 42,100
Farmer Mac Guaranteed Securities and USDA Securities
Amortized Cost
Due within one year	1,029,330
Due after one year through five years	900,448
Due after five years through ten years	255,611
Due after ten years	2,157,092
Amortized Cost	4,342,481	$ 4,469,702
Fair Value
Due within one year	1,027,276
Due after one year through five years	870,548
Due after five years through ten years	250,630
Due after ten years	2,119,098
Total	$ 4,267,552
Weighted- Average Yield
Due within one year	1.13%
Due after one year through five years	2.09%
Due after five years through ten years	2.79%
Due after ten years	3.14%
Total	2.41%