4. Debt (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Other debt outstanding	$ 72,698	$ 85,649
Warehouse lines of credit
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Other debt outstanding	$ 20,798	23,581
Interest rate	5.50% over one month Libor (Minimum 6.50%)
Maturity date	April 2019
Warehouse lines of credit (2)
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Other debt outstanding	$ 26,136	33,258
Interest rate	5.50% over one month Libor (Minimum 6.25%)
Maturity date	August 2017
Residual interest financing
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Other debt outstanding	$ 10,572	12,327
Interest rate	11.75% over one month Libor
Maturity date	April 2018
Debt secured by receivables measured at fair value
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Other debt outstanding	$ 0	1,250
Interest rate	n/a
Maturity date	Repayment is based on payments from underlying receivables. Final payment of the 8.00% loan was made in September 2013, while final residual payment was made in January 2015
Subordinated renewable notes
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Other debt outstanding	$ 15,192	$ 15,233
Interest rate	Weighted average rate of 9.45% and 10.7% at September 30, 2015 and December 31, 2014 , respectively
Maturity date	Weighted average maturity of March 2017 and October 2016 at September 30, 2015 and December 31, 2014, respectively

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

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

- Definition

Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

+ References

+ Details

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

- Definition

Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond 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 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

+ Details

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

- Details

Name:	us-gaap_CreditFacilityAxis=cpss_WarehouseLinesOfCredit1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=cpss_WarehouseLinesOfCredit2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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