XML 47 R55.htm IDEA: XBRL DOCUMENT
v3.19.3

Guarantees and Long-Term Standby Purchase Commitments - Long-Term Standby Purchase Commitments (Details) - Long-Term Standby Purchase Commitments [Member] - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2019 | Dec. 31, 2018
Guarantor Obligations [Line Items] |  |
Maximum principal amount of potential undiscounted future payments | $ 3,100.0 | $ 3,200.0
Weighted average remaining maturity, loans underlying guarantees not held by transferor | 15 years 2 months 12 days | 15 years 3 months 18 days
Guarantee obligations issued after January 1, 2003 [Member] |  |
Guarantor Obligations [Line Items] |  |
Guarantor obligation, liability | $ 35.0 | $ 35.9

X
- Definition Weighted average remaining maturity, Loans underlying guarantees not held by transferor + References No definition available. + Details
Name: | agm_WeightedAverageRemainingMaturityLoansUnderlyingGuaranteesNotHeldByTransferor
Namespace Prefix: | agm_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsCurrentCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_GuaranteeObligationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=agm_LongTermStandbyPurchaseCommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | agm_UnrecordedMaximumPotentialExposureOnGuaranteesAxis=agm_GuaranteeobligationsissuedafterJanuary12003Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |