FAIR VALUE DISCLOSURES - Schedule of Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Assets:
Financial derivatives	$ 27,867	$ 27,789
Liabilities:
Financial derivatives	63,389	77,326
Investment securities
Assets:
Available-for-sale, at fair value	6,230,080	$ 5,953,014
Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	$ 5,623,384
Level 3
Liabilities:
Percent of level three fair value assets and liabilities	18.00%	18.00%
Financial instruments level three percent	47.00%	48.00%
Recurring
Assets:
Loans held for sale, at lower of cost or fair value	$ 6,045	$ 6,160
Financial derivatives	27,867	27,789
Guarantee Asset	5,297	5,382
Total Assets at fair value	11,893,324	11,507,709
Liabilities:
Financial derivatives	63,389	77,326
Total Liabilities at fair value	63,389	77,326
Recurring | USDA Securities
Assets:
Trading	651	818
Recurring | Investment securities
Assets:
Available-for-sale, at fair value	6,230,080	5,953,014
Recurring | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	5,623,384	5,514,546
Recurring | Level 1
Assets:
Loans held for sale, at lower of cost or fair value	0	0
Financial derivatives	1	47
Guarantee Asset	0	0
Total Assets at fair value	1,314,719	1,289,893
Liabilities:
Financial derivatives	3	0
Total Liabilities at fair value	3	0
Recurring | Level 1 | USDA Securities
Assets:
Trading	0	0
Recurring | Level 1 | Investment securities
Assets:
Available-for-sale, at fair value	1,314,718	1,289,846
Recurring | Level 1 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
Recurring | Level 2
Assets:
Loans held for sale, at lower of cost or fair value	6,045	6,160
Financial derivatives	27,866	27,742
Guarantee Asset	0	0
Total Assets at fair value	4,929,920	4,677,594
Liabilities:
Financial derivatives	63,386	77,326
Total Liabilities at fair value	63,386	77,326
Recurring | Level 2 | USDA Securities
Assets:
Trading	0	0
Recurring | Level 2 | Investment securities
Assets:
Available-for-sale, at fair value	4,896,009	4,643,692
Recurring | Level 2 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	0	0
Recurring | Level 3
Assets:
Loans held for sale, at lower of cost or fair value	0	0
Financial derivatives	0	0
Guarantee Asset	5,297	5,382
Total Assets at fair value	5,648,685	5,540,222
Liabilities:
Financial derivatives	0	0
Total Liabilities at fair value	0	0
Recurring | Level 3 | USDA Securities
Assets:
Trading	651	818
Recurring | Level 3 | Investment securities
Assets:
Available-for-sale, at fair value	19,353	19,476
Recurring | Level 3 | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	5,623,384	5,514,546
AgVantage | Recurring | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	5,614,512	5,505,531
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	5,614,512	5,505,531
Farmer Mac Guaranteed USDA Securities | Recurring | Farmer Mac Guaranteed Securities
Assets:
Available-for-sale, at fair value	8,872	9,015
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	8,872	9,015
USDA Securities | Recurring | USDA Securities
Assets:
Trading	651	818
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	651	818
Floating interest rate | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	19,353	19,476
Floating interest rate | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,392,097	2,305,725
Floating interest rate | Recurring | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	19,353	19,476
Floating interest rate | Recurring | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,392,097	2,305,725
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 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	2,392,097	2,305,725
Floating interest rate | Recurring | Level 3 | Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Available-for-sale, at fair value	19,353	19,476
Floating interest rate | Recurring | Level 3 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	0	0
Fixed Interest Rate | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,503,912	2,337,967
Fixed Interest Rate | US treasuries
Assets:
Available-for-sale, at fair value	1,314,718	1,289,846
Fixed Interest Rate | Recurring | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,503,912	2,337,967
Fixed Interest Rate | Recurring | US treasuries
Assets:
Available-for-sale, at fair value	1,314,718	1,289,846
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	1,314,718	1,289,846
Fixed Interest Rate | Recurring | Level 2 | Guaranteed mortgage-backed securities
Assets:
Available-for-sale, at fair value	2,503,912	2,337,967
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