Fair Value Disclosures - Quantitative Information (Details) $ in Thousands	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 8,225,454
Recurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Guarantee Asset	4,570	$ 4,467
Recurring | Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	8,225,454	7,607,226
Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Guarantee Asset	4,570	4,467
Recurring | Level 3 | Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	8,225,454	7,607,226
Farmer Mac Guaranteed Securities | Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	8,000	7,800
AgVantage Securities | Recurring | Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	8,217,420	7,599,379
AgVantage Securities | Recurring | Level 3 | Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	8,217,420	7,599,379
Farmer Mac Guaranteed USDA Securities | Recurring | Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	8,034	7,847
Farmer Mac Guaranteed USDA Securities | Recurring | Level 3 | Farmer Mac Guaranteed Securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 8,034	$ 7,847
Range of broker quotes | Minimum | Floating rate auction-rate certificates backed by Government guaranteed student loans | Indicative bids | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.968	0.968
Range of broker quotes | Maximum | Floating rate auction-rate certificates backed by Government guaranteed student loans | Indicative bids | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.968	0.968
Range of broker quotes | Weighted Average | Floating rate auction-rate certificates backed by Government guaranteed student loans | Indicative bids | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.968	0.968
Discount rate | Minimum | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Guarantee asset, measurement input	0.050	0.054
Discount rate | Minimum | AgVantage Securities | Farmer Mac Guaranteed Securities | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.044	0.047
Discount rate | Minimum | Farmer Mac Guaranteed USDA Securities | Farmer Mac Guaranteed Securities | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.044	0.048
Discount rate | Minimum | USDA Securities | USDA Securities: | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
USDA securities, measurement input	0.049	0.051
Discount rate | Maximum | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Guarantee asset, measurement input	0.055	0.059
Discount rate | Maximum | AgVantage Securities | Farmer Mac Guaranteed Securities | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.063	0.061
Discount rate | Maximum | Farmer Mac Guaranteed USDA Securities | Farmer Mac Guaranteed Securities | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.049	0.053
Discount rate | Maximum | USDA Securities | USDA Securities: | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
USDA securities, measurement input	0.052	0.057
Discount rate | Weighted Average | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Guarantee asset, measurement input	0.052	0.057
Discount rate | Weighted Average | AgVantage Securities | Farmer Mac Guaranteed Securities | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.050	0.051
Discount rate | Weighted Average | Farmer Mac Guaranteed USDA Securities | Farmer Mac Guaranteed Securities | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.047	0.051
Discount rate | Weighted Average | USDA Securities | USDA Securities: | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
USDA securities, measurement input	0.051	0.053
CPR | Farmer Mac Guaranteed USDA Securities | Farmer Mac Guaranteed Securities | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment securities, measurement input	0.08	0.08
CPR | Minimum | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Guarantee asset, measurement input	0.08	0.08
CPR | Minimum | USDA Securities | USDA Securities: | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
USDA securities, measurement input	0.13	0.19
CPR | Maximum | USDA Securities | USDA Securities: | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
USDA securities, measurement input	0.13	0.27
CPR | Weighted Average | USDA Securities | USDA Securities: | Discounted cash flow | Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
USDA securities, measurement input	0.13	0.25