v2.4.0.6

Leases of Lessee Disclosure - Additional Information (Detail) (Office and Warehouse)	6 Months Ended
	Jun. 30, 2012
Office and Warehouse
Schedule of Operating Leases [Line Items]
Lease, expired 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:	crv_ScheduleOfOperatingLeasesLineItems
Namespace Prefix:	crv_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration