Contingencies and Commitments (Details 2) (Raw materials, USD $) In Millions, unless otherwise specified	12 Months Ended
Jun. 30, 2012
Raw materials
Purchase agreements
Aggregate purchase commitments	$ 422.3
Purchase commitments for fiscal year 2013	241.3
Purchase commitments for fiscal year 2014	45.1
Purchase commitments for fiscal year 2015	43.9
Purchase commitments for fiscal year 2016	45.2
Purchase commitments for fiscal year 2017	$ 46.8

The minimum amount that the entity agreed to spend under the long-term purchase commitment in the fifth year following the report date.

No definition available.

Name:	crs_LongTermPurchaseCommitmentYearFive
Namespace Prefix:	crs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The minimum amount that the entity agreed to spend under the long-term purchase commitment in the fourth year following the report date.

No definition available.

Name:	crs_LongTermPurchaseCommitmentYearFour
Namespace Prefix:	crs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The minimum amount that the entity has agreed to spend under the long-term purchase commitment in the year following the report date.

No definition available.

Name:	crs_LongTermPurchaseCommitmentYearOne
Namespace Prefix:	crs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The minimum amount that the entity agreed to spend under the long-term purchase commitment in the third year following the report date.

No definition available.

Name:	crs_LongTermPurchaseCommitmentYearThree
Namespace Prefix:	crs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The minimum amount that the entity agreed to spend under the long-term purchase commitment in the second year following the report date.

No definition available.

Name:	crs_LongTermPurchaseCommitmentYearTwo
Namespace Prefix:	crs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The minimum amount the entity agreed to spend under the long-term purchase commitment.

No definition available.

Name:	us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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