XML 41 R53.htm IDEA: XBRL DOCUMENT v3.3.0.814

Debt (Summary of Additional Information of Credit facilities) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revolving Secured Line of Credit [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	$ 142.6	$ 163.5	$ 206.3	$ 204.7
Average outstanding balance	30.0	101.2	48.0	102.2
Warehouse Facility II [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	200.8	290.2	200.8	290.2
Average outstanding balance	4.4	152.9	10.6	89.6
Warehouse Facility IV [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	12.0	26.7	35.0	26.7
Average outstanding balance	12.0	24.5	8.2	21.7
Warehouse Facility V [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	99.2	58.8	99.2	75.0
Average outstanding balance	9.6	2.5	16.4	7.4
Warehouse Facility VI [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	0.0	0.0	0.0
Average outstanding balance	$ 0.0	$ 0.0	$ 0.0	$ 0.0

X

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

X

- Definition

Average amount borrowed under the credit facility during the period.

+ References

No definition available.

+ Details

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

X

- Definition

Maximum amount borrowed under the credit facility at any time during the period.

+ References

No definition available.

+ Details

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

X

- Details

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

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cacc_WarehouseFacilityIIMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cacc_WarehouseFacilityIVMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cacc_WarehouseFacilityVMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=cacc_WarehouseFacilityVIMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: