Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Period End Date	dei_DocumentPeriodEndDate	Jul. 31, 2021
Registrant Name	dei_EntityRegistrantName	FEDERATED HERMES MONEY MARKET OBLIGATIONS TRUST
CIK	dei_EntityCentralIndexKey	0000856517
Amendment Flag	dei_AmendmentFlag	false
Document Created Date	dei_DocumentCreationDate	Sep. 27, 2021
Effective Date	dei_DocumentEffectiveDate	Sep. 28, 2021
Prospectus Date	rr_ProspectusDate	Sep. 30, 2021
Entity Inv Company Type	dei_EntityInvCompanyType	N-1A
Federated Hermes Capital Reserves Fund \| Federated Hermes Capital Reserves Fund
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	FRFXX
Federated Hermes Government Reserves Fund \| A
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GRAXX
Federated Hermes Government Reserves Fund \| B
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GRBXX
Federated Hermes Government Reserves Fund \| C
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GRCXX
Federated Hermes Government Reserves Fund \| F
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GRGXX
Federated Hermes Government Reserves Fund \| P
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GRFXX
Federated Hermes Government Obligations Fund \| SEL
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GRTXX
Federated Hermes Government Obligations Fund \| IS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOIXX
Federated Hermes Government Obligations Fund \| SS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOSXX
Federated Hermes Government Obligations Fund \| ADM
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOEXX
Federated Hermes Government Obligations Fund \| CII
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GFYXX
Federated Hermes Government Obligations Fund \| CS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GFSXX
Federated Hermes Government Obligations Fund \| CAP
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOCXX
Federated Hermes Government Obligations Fund \| TR
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GORXX
Federated Hermes Government Obligations Fund \| PRM
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOFXX
Federated Hermes Government Obligations Fund \| AVR
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOVXX
Federated Hermes Government Obligations Tax-Managed Fund \| AS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOAXX
Federated Hermes Government Obligations Tax-Managed Fund \| IS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GOTXX
Federated Hermes Government Obligations Tax-Managed Fund \| SS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	GTSXX
Federated Hermes Institutional Money Market Management \| IS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	MMPXX
Federated Hermes Institutional Money Market Management \| SS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	MMSXX
Federated Hermes Institutional Money Market Management \| CAP
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	MMLXX
Federated Hermes Institutional Money Market Management \| EAG
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	MMMXX
Federated Hermes Prime Cash Obligations Fund \| AS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PTAXX
Federated Hermes Prime Cash Obligations Fund \| R
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PTRXX
Federated Hermes Prime Cash Obligations Fund \| WS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PCOXX
Federated Hermes Prime Cash Obligations Fund \| AVR
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PCVXX
Federated Hermes Prime Cash Obligations Fund \| SS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PRCXX
Federated Hermes Prime Cash Obligations Fund \| CII
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PCDXX
Federated Hermes Prime Cash Obligations Fund \| CS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PTSXX
Federated Hermes Prime Cash Obligations Fund \| CAP
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PCCXX
Federated Hermes Prime Cash Obligations Fund \| TR
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PTTXX
Federated Hermes Institutional Prime Obligations Fund \| IS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	POIXX
Federated Hermes Institutional Prime Obligations Fund \| SS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PRSXX
Federated Hermes Institutional Prime Obligations Fund \| CAP
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	POPXX
Federated Hermes Institutional Prime Value Obligations Fund \| IS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PVOXX
Federated Hermes Institutional Prime Value Obligations Fund \| SS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PVSXX
Federated Hermes Institutional Prime Value Obligations Fund \| CAP
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PVCXX
Federated Hermes Treasury Obligations Fund \| AS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TOAXX
Federated Hermes Treasury Obligations Fund \| IS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TOIXX
Federated Hermes Treasury Obligations Fund \| SS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TOSXX
Federated Hermes Treasury Obligations Fund \| CAP
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TOCXX
Federated Hermes Treasury Obligations Fund \| TR
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TOTXX
Federated Hermes Trust for U S Treasury Obligations \| IS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TTOXX
Federated Hermes Trust for U S Treasury Obligations \| CII
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TTIXX
Federated Hermes Trust for U S Treasury Obligations \| CS
Risk Return Abstract	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	TCSXX

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

No definition available.

Name:	dei_AmendmentFlag
Namespace Prefix:	dei_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

The date the document was made available and submitted, in YYYY-MM-DD format. The date of submission, date of acceptance by the recipient, and the document effective date are all potentially different.

+ References

No definition available.

+ Details

Name:	dei_DocumentCreationDate
Namespace Prefix:	dei_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The date when a document, upon receipt and acceptance, becomes officially effective, in YYYY-MM-DD format. Usually it is a system-assigned date time value, but it may be declared by the submitter in some cases.

+ References

No definition available.

+ Details

Name:	dei_DocumentEffectiveDate
Namespace Prefix:	dei_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is YYYY-MM-DD.

+ References

No definition available.

+ Details

Name:	dei_DocumentPeriodEndDate
Namespace Prefix:	dei_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

+ References

No definition available.

+ Details

Name:	dei_DocumentType
Namespace Prefix:	dei_
Data Type:	dei:submissionTypeItemType
Balance Type:	na
Period Type:	duration

- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
-Number 240
-Section 12
-Subsection b-2

+ Details

Name:	dei_EntityCentralIndexKey
Namespace Prefix:	dei_
Data Type:	dei:centralIndexKeyItemType
Balance Type:	na
Period Type:	duration

- Definition

One of: N-1A (Mutual Fund), N-1 (Open-End Separate Account with No Variable Annuities), N-2 (Closed-End Investment Company), N-3 (Separate Account Registered as Open-End Management Investment Company), N-4 (Variable Annuity UIT Separate Account), N-5 (Small Business Investment Company), N-6 (Variable Life UIT Separate Account), S-1 or S-3 (Face Amount Certificate Company), S-6 (UIT, Non-Insurance Product).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-T
-Number 232
-Section 313

+ Details

Name:	dei_EntityInvCompanyType
Namespace Prefix:	dei_
Data Type:	dei:invCompanyType
Balance Type:	na
Period Type:	duration

- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
-Number 240
-Section 12
-Subsection b-2

+ Details

Name:	dei_EntityRegistrantName
Namespace Prefix:	dei_
Data Type:	xbrli:normalizedStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

Name:	dei_TradingSymbol
Namespace Prefix:	dei_
Data Type:	dei:tradingSymbolItemType
Balance Type:	na
Period Type:	duration

- Definition

The date of the prospectus.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 1
-Subsection a
-Paragraph 3

+ Details

Name:	rr_ProspectusDate
Namespace Prefix:	rr_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	rr_RiskReturnAbstract
Namespace Prefix:	rr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration