v2.4.0.8

Commitments - Additional Information (Detail) (Office and Warehouse)	3 Months Ended
	Mar. 31, 2014
Office and Warehouse
Operating Leased Assets [Line Items]
Lease, expiration period	10 years

X

- Definition

Operating Lease Expiration Period

+ References

No definition available.

+ Details

Name:	crv_OperatingLeaseExpirationPeriod
Namespace Prefix:	crv_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

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