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Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2018 USD ($) portfolio_segment segment | Dec. 31, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items] |  |
Future minimum lease payments | $ 5.4 |
Number of reportable segments | segment | 1 |
Uninsured cash and cash equivalents | $ 194.5 | $ 7.8
Number of portfolio segments | portfolio_segment | 2 |
Period after Consumer Loan assignment that Dealer Loans written off | 120 months |
Period after month of purchase that Purchased Loans written off | 120 months |
Restricted Cash and Cash Equivalents [Member] |  |
Summary Of Significant Accounting Policies [Line Items] |  |
Uninsured cash and cash equivalents | $ 347.0 | $ 255.1

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- Definition Period After Determination Dealer Loan Write Off + References No definition available. + Details
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- Definition Contractually required future rental payments receivable on noncancelable subleasing arrangements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717 + Details
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- Details
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