| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Cover [Abstract] | |
| Document Type | DEF 14A |
| Entity Registrant Name | FEDERAL AGRICULTURAL MORTGAGE CORPORATION |
| Entity Central Index Key | 0000845877 |
| Amendment Flag | false |
| Pay vs Performance Disclosure - USD ($) | 12 Months Ended | |||
| Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | ||
| Pay vs Performance Disclosure [Table] | ||||
| Pay vs Performance [Table Text Block] | 1 1,2 1 1,2 3 4 5 Value of Initial Fixed $100 Year Summary 1 Compensation 1,2 Average Summary 1 Average 1,2 Farmer 3 Peer Group 4 Net Income Earnings 5 2022 $3,532,666 $3,094,824 $1,136,013 $1,033,285 $152 $134 $178,144,000 $125,598,000 2021 $3,211,156 $5,060,035 $1,045,533 $1,465,036 $161 $151 $136,089,000 $111,842,000 2020 $2,680,795 $2,445,320 $1,117,787 $1,022,015 $ 93 $111 $114,376,000 $106,639,000 | |||
| Named Executive Officers, Footnote [Text Block] | Mr. Nordholm | |||
| PEO Total Compensation Amount | [1] | $ 3,532,666 | $ 3,211,156 | $ 2,680,795 |
| PEO Actually Paid Compensation Amount | [1],[2] | 3,094,824 | 5,060,035 | 2,445,320 |
| Non-PEO NEO Average Total Compensation Amount | [1] | 1,136,013 | 1,045,533 | 1,117,787 |
| Non-PEO NEO Average Compensation Actually Paid Amount | [1],[2] | $ 1,033,285 | 1,465,036 | 1,022,015 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | The Non-PEO NEOs included for 2021 and 2022 consisted of Ms. Ramesh, Mr. Carpenter, Mr. Crady, and Mr. Mullery. The Non-PEO NEOs included for 2020 consisted of Ms. Ramesh, Mr. Carpenter, Mr. Mullery, and former executive officer John C. Covington. | |||
| Tabular List [Table Text Block] | Most Important Measures to Determine 2022 CAP In Farmer Mac’s assessment, the seven metrics listed below represent the most important financial performance measures that Farmer Mac used to link each NEO’s compensation to Farmer Mac’s performance in 2022. Each of the listed financial measures was either used in the balanced “scorecard” to determine annual short-term incentive compensation awards for performance in 2022 or to determine the vesting of long-term performance-based RSUs that vested in 2022: Earnings (Core Earnings before Credit) Total Revenues Business Volume Ratio of Substandard Assets to Regulatory Capital Compliance with applicable capital requirements Net charge-offs 90-day delinquencies These measures are not listed or ranked in any particular order and are further described above in “Compensation Discussion and Analysis—Approach to Incentive Compensation,” “—Total Compensation Elements—Annual Cash Incentive Compensation” and “—Total Compensation Elements—Long-Term Incentive Compensation.” Although it is always a challenge to narrow down to a few measures, the Compensation Committee chose these measures because they most closely represent the business goals established by the Board and management for 2022 and balance the need for business volume growth, earnings, disciplined underwriting, high credit quality, and continued financial stability with the enhancement of stockholder value. Farmer Mac believes that Earnings (sometimes referred to as Core Earnings before Credit) is the most important financial performance measure tied to executive compensation. Earnings is used to determine 25% of annual short-term incentive compensation awards and most appropriately reflects Farmer Mac’s overall performance over the short-term. Cumulative three-year Earnings is also the primary measure used to determine the vesting of performance-based RSUs granted to the NEOs in 2022 and 2023. | |||
| Total Shareholder Return Amount | [3] | $ 152 | 161 | 93 |
| Peer Group Total Shareholder Return Amount | [4] | 134 | 151 | 111 |
| Net Income (Loss) | $ 178,144,000 | $ 136,089,000 | $ 114,376,000 | |
| Company Selected Measure Amount | [5] | 125,598,000 | 111,842,000 | 106,639,000 |
| PEO Name | Mr. Nordholm | |||
| Measure [Axis]: 1 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Earnings (Core Earnings before Credit) | |||
| Measure [Axis]: 2 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Total Revenues | |||
| Measure [Axis]: 3 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Business Volume | |||
| Measure [Axis]: 4 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Ratio of Substandard Assets to Regulatory Capital | |||
| Measure [Axis]: 5 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Compliance with applicable capital requirements | |||
| Measure [Axis]: 6 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | Net charge-offs | |||
| Measure [Axis]: 7 | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Measure Name | 90-day delinquencies | |||
| PEO [Member] | Cumulative Deductions from SCT Total | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | [6] | $ 1,574,299 | $ 1,095,102 | $ 1,093,672 |
| PEO [Member] | Cumulative Additions to SCT Total | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | [7] | 1,136,457 | 2,943,981 | 858,197 |
| PEO [Member] | Aggregate change in actuarial present value included in SCT Amounts for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| PEO [Member] | Service cost for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| PEO [Member] | Prior service cost for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| PEO [Member] | Aggregate value for stock awards and option awards included in SCT Amounts for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | (1,175,634) | (1,095,102) | (852,948) | |
| PEO [Member] | Fair value at year end of awards granted during the covered fiscal year that were outstanding and unvested at the covered fiscal year end | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | 940,719 | 1,716,391 | 858,197 | |
| PEO [Member] | Year-over-year change in fair value at covered fiscal year end of awards granted in any prior fiscal year that were outstanding and unvested at the covered fiscal year end | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | (149,823) | 892,796 | (139,027) | |
| PEO [Member] | Vesting date fair value of awards granted and vested during the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | 195,738 | |||
| PEO [Member] | Change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | (248,843) | 334,795 | (101,697) | |
| PEO [Member] | Fair value at end of prior fiscal year of awards granted in any prior fiscal year that failed to meet the applicable vesting conditions during the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| PEO [Member] | Dividends or other earnings paid on stock or option awards in the covered fiscal year prior to vesting if not otherwise included in the total compensation for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| Non-PEO NEO [Member] | Cumulative Deductions from SCT Total | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | [8] | 368,737 | 291,803 | 385,762 |
| Non-PEO NEO [Member] | Cumulative Additions to SCT Total | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | [9] | 266,009 | 711,306 | 289,990 |
| Non-PEO NEO [Member] | Aggregate change in actuarial present value included in SCT Amounts for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| Non-PEO NEO [Member] | Service cost for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| Non-PEO NEO [Member] | Prior service cost for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| Non-PEO NEO [Member] | Aggregate value for stock awards and option awards included in SCT Amounts for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | (277,089) | (291,803) | (285,622) | |
| Non-PEO NEO [Member] | Fair value at year end of awards granted during the covered fiscal year that were outstanding and unvested at the covered fiscal year end | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | 266,009 | 457,320 | 289,990 | |
| Non-PEO NEO [Member] | Year-over-year change in fair value at covered fiscal year end of awards granted in any prior fiscal year that were outstanding and unvested at the covered fiscal year end | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | (41,443) | 200,666 | (28,588) | |
| Non-PEO NEO [Member] | Vesting date fair value of awards granted and vested during the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| Non-PEO NEO [Member] | Change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | (50,205) | 53,320 | (71,553) | |
| Non-PEO NEO [Member] | Fair value at end of prior fiscal year of awards granted in any prior fiscal year that failed to meet the applicable vesting conditions during the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| Non-PEO NEO [Member] | Dividends or other earnings paid on stock or option awards in the covered fiscal year prior to vesting if not otherwise included in the total compensation for the covered fiscal year | ||||
| Pay vs Performance Disclosure [Table] | ||||
| Adjustment to Compensation Amount | ||||
| Peo 1 [Member] | ||||
| Pay vs Performance Disclosure [Table] | ||||
| PEO Total Compensation Amount | 3,532,666 | 3,211,156 | 2,680,795 | |
| PEO Actually Paid Compensation Amount | 3,094,824 | 5,060,035 | 2,445,320 | |
| Non-PEO NEO Average Total Compensation Amount | 1,136,013 | 1,045,533 | 1,117,787 | |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 1,033,285 | $ 1,465,036 | $ 1,022,015 | |
| [1] Mr. Nordholm The Non-PEO NEOs included for 2021 and 2022 consisted of Ms. Ramesh, Mr. Carpenter, Mr. Crady, and Mr. Mullery. The Non-PEO NEOs included for 2020 consisted of Ms. Ramesh, Mr. Carpenter, Mr. Mullery, and former executive officer John C. Covington. | ||||
