Name:	atlc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityRevaluationsOfNotesPayable
Namespace Prefix:	atlc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Fees and related income on earning assets primarily include: (1) lending fees; (2) fees associated with our credit card receivables; (3) changes in the fair value of loans and fees receivable; (4) changes in fair value of notes payable associated with structured financings; (5) income on investments in previously charged-off receivables; (6) gross profits and losses from auto sales; (7) gains associated with investments in securities; and (8) gains realized associated with our settlement of litigation.

No definition available.

Name:	atlc_FeesAndRelatedIncomeOnEarningAssets
Namespace Prefix:	atlc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the amount of revenue related to fees on credit products.

No definition available.

Name:	atlc_FeesOnCreditProducts
Namespace Prefix:	atlc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the increase (decrease) during the period in the fair value of loans and fees receivable.

No definition available.

Name:	atlc_IncreaseDecreaseInFairValueOfLoansAndFeesReceivableRecordedAtFairValue
Namespace Prefix:	atlc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227