Farmer Mac Guaranteed Securities and USDA Securities - Schedule of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
AgVantage
Weighted- Average Yield
Available-for-sale, accrued interest excluded	$ 29,800	$ 32,300
Farmer Mac Guaranteed Securities
Amortized Cost
Due within one year	1,401,396
Due after one year through five years	2,142,369
Due after five years through ten years	1,008,986
Due after ten years	1,583,056
Debt securities, available-for-sale, amortized cost	6,135,807
Fair Value
Due within one year	1,408,170
Due after one year through five years	2,194,055
Due after five years through ten years	1,034,586
Due after ten years	1,691,748
Total, Fair Value	$ 6,328,559
Weighted- Average Yield
Due within one year	1.80%
Due after one year through five years	2.52%
Due after five years through ten years	2.21%
Due after ten years	2.46%
Total, Weighted-Average Yield	2.28%
Farmer Mac Guaranteed Securities | AgVantage
Amortized Cost
Debt securities, available-for-sale, amortized cost		6,594,992
Fair Value
Total, Fair Value		$ 6,947,701