FAIR VALUE DISCLOSURES - Schedule of Fair Value Inputs, Assets and Liabilities, Quantitative Information (Details) $ in Thousands	Jun. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 14,891,506	$ 13,580,285
Other Assets	4,852	4,897
ABS
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	65,474
AgVantage
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	7,702,969	6,730,917
Interest-Only Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	8,126	8,203
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other Assets	$ 4,852	$ 4,897
Level 3 | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other asset, measurement input	0.081	0.078
Level 3 | CPR | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other asset, measurement input	0.023	0.033
Level 3 | ABS
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 65,474
Level 3 | ABS | Minimum | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.058
Level 3 | ABS | Maximum | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.075
Level 3 | ABS | Weighted Average | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.070
Level 3 | AgVantage
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 7,702,969	$ 6,730,917
Level 3 | AgVantage | Minimum | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.048	0.043
Level 3 | AgVantage | Maximum | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.056	0.049
Level 3 | AgVantage | Weighted Average | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.050	0.045
Level 3 | Interest-Only Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 8,126	$ 8,203
Level 3 | Interest-Only Farmer Mac Guaranteed Securities | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.081	0.078
Level 3 | Interest-Only Farmer Mac Guaranteed Securities | CPR | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.023	0.033