XML 23 R32.htm IDEA: XBRL DOCUMENT v2.4.1.9
Subsequent Events - Additional Information (Detail) (Subsequent Event, USD $)
In Millions, unless otherwise specified
 0 Months Ended
May 04, 2015
May 04, 2015
20th Amendment
    
Subsequent Event [Line Items]    
Line of credit facility extended maturity date period 1 year  
Revolving line of credit extended maturity date Jul. 10, 2018  
Maximum borrowings available under line of credit $ 30us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ crv_AmendmentAxis
= crv_AmendedCreditFacilityMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		 $ 30us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ crv_AmendmentAxis
= crv_AmendedCreditFacilityMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
Line of credit facility, reduction in interest rate 0.25%crv_LineOfCreditFacilityReductionInInterestRate
/ crv_AmendmentAxis
= crv_AmendedCreditFacilityMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember		 0.25%crv_LineOfCreditFacilityReductionInInterestRate
/ crv_AmendmentAxis
= crv_AmendedCreditFacilityMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
Before Amendment
    
Subsequent Event [Line Items]    
Revolving line of credit maturity date Jul. 10, 2017