Approximate size of referenced site.

No definition available.

Name:	cr_ApproximateSizeOfReferencedSite
Namespace Prefix:	cr_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Gross settlement and defense costs incurred (before insurance recoveries and tax effects).

+ References

No definition available.

+ Details

Name:	cr_GrossSettlementAndDefenseIncurredCosts
Namespace Prefix:	cr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loss Contingency Reimbursement rate for qualifying costs of investigation and remediation activities.

+ References

No definition available.

+ Details

Name:	cr_LossContingencyReimbursementRate
Namespace Prefix:	cr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total costs accrued as of the balance sheet date for environmental loss contingencies.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

+ Details

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

- Definition

Amount of expense (reversal of expense) which increases (decreases) the accrual for environmental loss contingencies from revisions in estimates to existing obligations. Excludes changes related to business acquisitions, divestitures, or currency movement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 5.Y.Q2)
-URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751

+ Details

Name:	us-gaap_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForRevisionInEstimates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 10
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6911-107765

+ Details

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

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

- Definition

Carrying amount as of the balance sheet date of known and reasonably estimable amounts of recoveries from third-parties pertaining to an entity's environmental remediation obligations. An entity's balance sheet may include several assets that relate to an environmental remediation obligation. Among them are the following: a. Receivables from other potentially responsible parties that are not providing initial funding; b. anticipated recoveries from insurers; and c. anticipated recoveries from prior owners as a result of indemnification agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237650&loc=d3e13022-110858

+ Details

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

- Details

Name:	cr_CommitmentsAndContingenciesAxis=cr_AsbestosCommitmentsAndContingenciesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cr_CommitmentsAndContingenciesAxis=cr_EnvironmentalClaimsForSiteInGoodyearArizonaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cr_CommitmentsAndContingenciesAxis=cr_EnvironmentalClaimsForCrabOrchardNationalWildlifeRefugeSuperfundSiteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies (Other Contingencies) (Detail) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2012 a
Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Gross Settlement And Defense Incurred Costs	$ 6.3	$ 13.9		$ 30.2	$ 54.2	$ 66.2
Environmental Claims For A Site In Goodyear Arizona
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates			$ 49.0			$ 18.9
Estimated liability	41.1			41.1
Accrued environmental loss contingencies current	$ 10.9			$ 10.9
Loss Contingency Reimbursement Rate	21.00%			21.00%
Other receivables	$ 7.8			$ 7.8
Environmental Claims For Crab Orchard National Wildlife Refuge Superfund Site
Loss Contingencies [Line Items]
Approximate Size Of Referenced Site \| a							55,000