Financial Instruments (Fair Value Measurements) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Derivatives, Fair Value [Line Items]
Collateral posted to counterparties	$ 0
Fair value of long-term debt compared with carrying value	437
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of long-term debt	4,524
Cash Flow Hedging [Member] \| Foreign Exchange Contract [Member] \| Assets [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	20	18
Cash Flow Hedging [Member] \| Foreign Exchange Contract [Member] \| Other Liabilities [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	10	17
Cash Flow Hedging [Member] \| Commodity Contract [Member] \| Assets [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	3	2
Cash Flow Hedging [Member] \| Commodity Contract [Member] \| Other Liabilities [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	$ 4	$ 8

The aggregate fair value of long term debt in excess of/(less than) the related carrying value.

No definition available.

Name:	emr_FairValueLongTermDebtComparedWithCarryingValue
Namespace Prefix:	emr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4H

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624258-113959

+ Details

Name:	us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=34720828&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (a),(c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624163-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 20

-Section 55

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=36459792&loc=SL20226000-175313

+ Details

Name:	us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

+ Details

Name:	us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DerivativesFairValueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant