FAIR VALUE DISCLOSURES - Schedule of Fair Value Inputs, Assets and Liabilities, Quantitative Information (Details) $ in Thousands	Sep. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 14,885,573	$ 13,580,285
Other Assets	4,683	4,897
ABS
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	61,026
AgVantage
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	7,493,597	6,730,917
Interest-Only Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	7,843	8,203
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other Assets	$ 4,683	$ 4,897
Level 3 | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other asset, measurement input	0.085	0.078
Level 3 | CPR | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other asset, measurement input	0.022	0.033
Level 3 | ABS
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 61,026
Level 3 | ABS | Minimum | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.067
Level 3 | ABS | Maximum | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.085
Level 3 | ABS | Weighted Average | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.079
Level 3 | AgVantage
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 7,493,597	$ 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	0.052	0.043
Level 3 | AgVantage | Maximum | Discount rate | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.061	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	0.057	0.045
Level 3 | Interest-Only Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS investment securities	$ 7,843	$ 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	0.085	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	0.022	0.033