XML 48 R74.htm IDEA: XBRL DOCUMENT
v3.20.1

Fair Value Disclosures - Narrative (Details) - Level 3 | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Percent of level three fair value assets and liabilities | 33.00% | 33.00%
Financial instruments level three percent | 72.00% | 71.00%

X
- Definition Fair Value, Assets and Liabilities Fair Value as Percent of Total Assets + References No definition available. + Details
Name: | agm_FairValueAssetsAndLiabilitiesFairValueAsPercentOfTotalAssets
Namespace Prefix: | agm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair Value, Assets and Liabilities, Fair Value as Percent of Total Financial Instruments Measured at Fair Value + References No definition available. + Details
Name: | agm_FairValueAssetsAndLiabilitiesFairValueAsPercentOfTotalFinancialInstrumentsMeasuredAtFairValue
Namespace Prefix: | agm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |