v3.2.0.727

Subsequent Event - Additional Information (Detail) - Jul. 08, 2015 - Subsequent Event - $ / shares	Total
Subsequent Event [Line Items]
Cash tender offer to purchase all of the issued and outstanding shares, purchase price	$ 5.50
Tender cash offer expiration date	Aug. 18, 2015
Percentage of outstanding shares by the holders	51.00%

X

- Definition

Business Acquisition, Offer Expiration Date

+ References

No definition available.

+ Details

Name:	crv_BusinessAcquisitionOfferExpirationDate
Namespace Prefix:	crv_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 805



-SubTopic 10



-Section 50



-Paragraph 2



-Subparagraph (c)



-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionSharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: