9. Interest Income and Interest Expense (Details - Interest Income) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest Income And Interest Expense
Interest on Finance Receivables	$ 286,361us-gaap_InvestmentIncomeNet	$ 231,320us-gaap_InvestmentIncomeNet	$ 174,019us-gaap_InvestmentIncomeNet
Residual interest income	372cpss_ResidualInterestIncome	0cpss_ResidualInterestIncome	458cpss_ResidualInterestIncome
Other interest income	1us-gaap_InterestAndOtherIncome	10us-gaap_InterestAndOtherIncome	837us-gaap_InterestAndOtherIncome
Interest income	$ 286,734	$ 231,330	$ 175,314

Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7(a),(b))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.9)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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