FAIR VALUE DISCLOSURES - Schedule of Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Financial derivatives	$ 31,433	$ 37,478
Liabilities:
Financial derivatives	128,530	117,131
Investment Securities
Assets:
Available-for-sale, at fair value	5,007,787	$ 4,918,931
Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	$ 5,466,688
Level 3
Liabilities:
Percent of level three fair value assets and liabilities	18.00%	19.00%
Financial instruments level three percent	52.00%	52.00%
Recurring
Assets:
Financial derivatives	$ 31,433	$ 37,478
Guarantee Asset	5,733	5,831
Total Assets at fair value	10,512,707	10,495,960
Liabilities:
Financial derivatives	128,530	117,131
Total Liabilities at fair value	128,530	117,131
Recurring | USDA Securities:
Assets:
Trading	1,066	1,241
Recurring | Investment Securities
Assets:
Available-for-sale, at fair value	5,007,787	4,918,931
Recurring | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	5,466,688	5,532,479
Recurring | Level 1
Assets:
Financial derivatives	680	11
Guarantee Asset	0	0
Total Assets at fair value	936,732	905,811
Liabilities:
Financial derivatives	0	91
Total Liabilities at fair value	0	91
Recurring | Level 1 | USDA Securities:
Assets:
Trading	0	0
Recurring | Level 1 | Investment Securities
Assets:
Available-for-sale, at fair value	936,052	905,800
Recurring | Level 1 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
Recurring | Level 2
Assets:
Financial derivatives	30,753	37,467
Guarantee Asset	0	0
Total Assets at fair value	4,083,207	4,031,516
Liabilities:
Financial derivatives	128,530	117,040
Total Liabilities at fair value	128,530	117,040
Recurring | Level 2 | USDA Securities:
Assets:
Trading	0	0
Recurring | Level 2 | Investment Securities
Assets:
Available-for-sale, at fair value	4,052,454	3,994,049
Recurring | Level 2 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
Recurring | Level 3
Assets:
Financial derivatives	0	0
Guarantee Asset	5,733	5,831
Total Assets at fair value	5,492,768	5,558,633
Liabilities:
Financial derivatives	0	0
Total Liabilities at fair value	0	0
Recurring | Level 3 | USDA Securities:
Assets:
Trading	1,066	1,241
Recurring | Level 3 | Investment Securities
Assets:
Available-for-sale, at fair value	19,281	19,082
Recurring | Level 3 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	5,466,688	5,532,479
AgVantage | Recurring | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	5,457,197	5,522,712
AgVantage | Recurring | Level 1 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
AgVantage | Recurring | Level 2 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
AgVantage | Recurring | Level 3 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	5,457,197	5,522,712
Farmer Mac Guaranteed USDA Securities | Recurring | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	9,491	9,767
Farmer Mac Guaranteed USDA Securities | Recurring | Level 1 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
Farmer Mac Guaranteed USDA Securities | Recurring | Level 2 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
Farmer Mac Guaranteed USDA Securities | Recurring | Level 3 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	9,491	9,767
USDA Securities | Recurring | USDA Securities:
Assets:
Trading	1,066	1,241
USDA Securities | Recurring | Level 1 | USDA Securities:
Assets:
Trading	0	0
USDA Securities | Recurring | Level 2 | USDA Securities:
Assets:
Trading	0	0
USDA Securities | Recurring | Level 3 | USDA Securities:
Assets:
Trading	1,066	1,241
Floating interest rate | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	19,281	19,082
Floating interest rate | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,380,066	2,424,434
Floating interest rate | US Treasuries
Assets:
Available-for-sale, at fair value	49,996	49,968
Floating interest rate | Recurring | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	19,281	19,082
Floating interest rate | Recurring | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,380,066	2,424,434
Floating interest rate | Recurring | Floating rate U.S. Treasuries
Assets:
Available-for-sale, at fair value	49,996	49,968
Floating interest rate | Recurring | Level 1 | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	0	0
Floating interest rate | Recurring | Level 1 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	0	0
Floating interest rate | Recurring | Level 1 | Floating rate U.S. Treasuries
Assets:
Available-for-sale, at fair value	49,996	49,968
Floating interest rate | Recurring | Level 2 | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	0	0
Floating interest rate | Recurring | Level 2 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,380,066	2,424,434
Floating interest rate | Recurring | Level 2 | Floating rate U.S. Treasuries
Assets:
Available-for-sale, at fair value	0	0
Floating interest rate | Recurring | Level 3 | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	19,281	19,082
Floating interest rate | Recurring | Level 3 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	0	0
Floating interest rate | Recurring | Level 3 | Floating rate U.S. Treasuries
Assets:
Available-for-sale, at fair value	0	0
Fixed Interest Rate | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	1,672,388	1,569,615
Fixed Interest Rate | US Treasuries
Assets:
Available-for-sale, at fair value	886,056	855,832
Fixed Interest Rate | Recurring | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	1,672,388	1,569,615
Fixed Interest Rate | Recurring | US Treasuries
Assets:
Available-for-sale, at fair value	886,056	855,832
Fixed Interest Rate | Recurring | Level 1 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	0	0
Fixed Interest Rate | Recurring | Level 1 | US Treasuries
Assets:
Available-for-sale, at fair value	886,056	855,832
Fixed Interest Rate | Recurring | Level 2 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	1,672,388	1,569,615
Fixed Interest Rate | Recurring | Level 2 | US Treasuries
Assets:
Available-for-sale, at fair value	0	0
Fixed Interest Rate | Recurring | Level 3 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	0	0
Fixed Interest Rate | Recurring | Level 3 | US Treasuries
Assets:
Available-for-sale, at fair value	$ 0	$ 0