The maximum annual limit for capital expenditures under the terms of the debt instrument.

No definition available.

Name:	crvp_DebtInstrumentCovenantMaximiumAnnualLimitForCapitalExpenditures
Namespace Prefix:	crvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The maximum senior funded debt to consolidated adjusted earnings before interest, taxes, depreciation, and amortized (EBITDA) allowed under the debt instrument covenant terms.

+ References

No definition available.

+ Details

Name:	crvp_DebtInstrumentCovenantMaximumSeniorFundedDebtToConsolidatedAdjustedEBITDA
Namespace Prefix:	crvp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

The minimum consolidated adjusted operating cash flows to consolidated total debt ratio allowed under the covenant terms of the debt instrument.

+ References

No definition available.

+ Details

Name:	crvp_DebtInstrumentCovenantTotalDebtCoverageRatio
Namespace Prefix:	crvp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the maximum amount that the company is allowed to prepay in aggregate of subordinated debt.

+ References

No definition available.

+ Details

Name:	crvp_DebtInstrumentMaximumAmountAllowedToPrepayInSubordinatedDebt
Namespace Prefix:	crvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the maximum amount from proceeds of the revolving credit line that can be used to pay subordinated debt.

+ References

No definition available.

+ Details

Name:	crvp_DebtInstrumentMaximumAmountAllowedToUseFromRevolvingLineOfCreditToPaySubordinatedDebt
Namespace Prefix:	crvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of each monthly installment to be paid throughout the life of a debt instrument.

+ References

No definition available.

+ Details

Name:	crvp_DebtInstrumentMonthlyInstallmentAmount
Namespace Prefix:	crvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of equal monthly installments to be paid on a debt instrument.

+ References

No definition available.

+ Details

Name:	crvp_DebtInstrumentNumberOfEqualMonthlyInstallments
Namespace Prefix:	crvp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate used to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	crvp_DebtInstrumentVariableRateBasis
Namespace Prefix:	crvp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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

- Definition

Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow from the repayment of long-term borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets or underlying collateral.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

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

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_ShortTermBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_SubordinatedDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CounterpartyNameAxis=crvp_PeterAndJackBakerAndTheEstateOfHenryBakerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CounterpartyNameAxis=crvp_PeterAndJohnBakerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=crvp_BankOfAmericaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=crvp_TermNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 3 - Debt (Details Textual)		9 Months Ended
Note 3 - Debt (Details Textual)	Jun. 13, 2017 USD ($)	Jul. 31, 2017 USD ($)	Jun. 12, 2017 USD ($)	Oct. 31, 2016 USD ($)	Sep. 12, 2016 USD ($)	May 20, 2015 USD ($)
Short-term Debt		$ 2,000,000
Peter and Jack Baker and the Estate of Henry Baker [Member]
Repayments of Subordinated Debt	$ 4,500,000
Peter and John Baker [Member]
Subordinated Debt		$ 4,500,000
Debt Instrument, Interest Rate, Stated Percentage		12.00%
Bank of America [Member]
Debt Instrument, Covenant, Maximium Annual Limit for Capital Expenditures					$ 4,000,000
Debt Instrument, Covenant, Total Debt Coverage Ratio					1.5
Debt Instrument, Covenant, Maximum Senior Funded Debt to Consolidated Adjusted EBITDA					2.5
Debt Instrument, Maximum Amount Allowed to Use from Revolving Line of Credit to Pay Subordinated Debt	2,000,000
Debt Instrument, Maximum Amount Allowed to Prepay in Subordinated Debt	4,500,000
Letters of Credit Outstanding, Amount		$ 1,327,000
Bank of America [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Variable Rate Basis		1.22%
Bank of America [Member] \| Revolving Credit Facility [Member]
Debt Instrument, Interest Rate, Effective Percentage		3.47%
Line of Credit Facility, Maximum Borrowing Capacity	$ 6,000,000		$ 5,000,000			$ 5,000,000
Line of Credit Facility, Remaining Borrowing Capacity		$ 2,673,000
Bank of America [Member] \| Revolving Credit Facility [Member] \| Line of Credit [Member]
Short-term Debt		$ 2,000,000
Bank of America [Member] \| Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate		2.25%
Bank of America [Member] \| Term Note [Member]
Long-term Debt		$ 8,533,000				$ 12,000,000
Debt Instrument, Interest Rate, Effective Percentage		3.72%
Debt Instrument, Term	5 years
Debt Instrument, Number of Equal Monthly Installments	59
Debt Instrument, Monthly Installment, Amount	$ 133,333
Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid	$ 4,133,333
Bank of America [Member] \| Term Note [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate		2.50%
Long-term Debt		$ 4,266,000