Line of credit facility maximum borrowed amount paid.

No definition available.

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Namespace Prefix:	cprt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line of Credit, Maximum Borrowing Capacity, Increase

+ References

No definition available.

+ Details

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Namespace Prefix:	cprt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

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

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
-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 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: 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_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- 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 the required periodic payment applied to principal.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ 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 (e)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

+ Details

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

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

+ Details

Name:	us-gaap_UnamortizedDebtIssuanceExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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- Details

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- Details

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- Details

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- Details

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Long-Term Debt (Details) - USD ($) $ in Thousands		9 Months Ended		12 Months Ended	47 Months Ended
Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 03, 2014	Apr. 30, 2016	Apr. 30, 2015	Dec. 31, 2015	Dec. 03, 2019	Mar. 15, 2016	Sep. 29, 2011	Dec. 14, 2010
Line of Credit Facility [Line Items]
Debt issuance cost		$ 165	$ 955
Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity								$ 100,000
Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity							$ 500,000	400,000
Alternative currency borrowing credit facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity								100,000
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity								$ 50,000
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of credit facility amount paid	$ 275,000
Credit Agreement [Member] \| Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	300,000
Outstanding borrowings		$ 0
Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Commitment fee percentage		0.15%
Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Commitment fee percentage		0.30%
Credit Agreement [Member] \| Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	300,000
Outstanding borrowings		$ 300,000
Maturity date		Dec. 03, 2019
Quarterly amortization for term loan				$ 18,800
LIBOR variable interest rate		LIBOR rate of 0.44% plus an applicable margin of 1.375%.
First Amendment To Credit Agreement [Member] \| Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 350,000
Line of Credit, Maximum Borrowing Capacity, Increase						50,000
First Amendment To Credit Agreement [Member] \| Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity						93,800
Outstanding borrowings						$ 93,800
Maturity date		Mar. 15, 2021
Note Purchase Agreement [Member]
Line of Credit Facility [Line Items]
Debt issuance cost		$ 2,500
Debt issuance fees		1,100
Reduction of long term debt		$ 1,400
Note Purchase Agreement [Member] \| Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt instrument principal amount	400,000
Note Purchase Agreement [Member] \| Senior Notes, Series A [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2024
Debt instrument principal amount	$ 100,000
Debt instrument, interest rate	4.07%
Note Purchase Agreement [Member] \| Senior Notes, Series B [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2026
Debt instrument principal amount	$ 100,000
Debt instrument, interest rate	4.19%
Note Purchase Agreement [Member] \| Senior Notes, Series C [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2027
Debt instrument principal amount	$ 100,000
Debt instrument, interest rate	4.25%
Note Purchase Agreement [Member] \| Senior Notes, Series D [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2029
Debt instrument principal amount	$ 100,000
Debt instrument, interest rate	4.35%
Scenario, Forecast [Member] \| Credit Agreement [Member] \| Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Quarterly amortization for term loan					$ 7,500
Federal Funds Effective Swap Rate [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		0.50%
London Interbank Offered Rate (LIBOR) [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		1.00%
London Interbank Offered Rate (LIBOR), Adjusted LIBOR One [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		0.125%
London Interbank Offered Rate (LIBOR), Adjusted LIBOR One [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		1.00%
London Interbank Offered Rate (LIBOR) Adjusted LIBOR Two [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		1.125%
London Interbank Offered Rate (LIBOR) Adjusted LIBOR Two [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		2.00%