Farmer Mac Guaranteed Securities and USDA Securities - Schedule of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
AgVantage
Weighted- Average Yield
Available-for-sale, accrued interest excluded	$ 53,300	$ 51,500
Farmer Mac Guaranteed Securities
Amortized Cost
Due within one year	693,100
Due after one year through five years	2,739,174
Due after five years through ten years	1,142,500
Due after ten years	961,663
Available-for-sale, Amortized Cost	5,536,437
Fair Value
Due within one year	682,379
Due after one year through five years	2,579,604
Due after five years through ten years	997,848
Due after ten years	798,866
Total, Fair Value	$ 5,058,697
Weighted- Average Yield
Due within one year	3.25%
Due after one year through five years	3.47%
Due after five years through ten years	3.27%
Due after ten years	3.55%
Total, Weighted-Average Yield	3.41%