MORTGAGE SERVICING RIGHTS (Details) (USD $)	3 Months Ended
Mar. 31, 2014 item
MORTGAGE SERVICING RIGHTS
Number of loans held under MSR portfolio	989
Unpaid principal amount on servicing assets	$ 3,800,000,000
Activity related to MSRs
Beginning balance	59,640,000
Additions, following sale of loan	2,500,000
Change in fair value	(1,847,000)
Prepayments and write-offs	(161,000)
Ending balance	60,132,000
Discount rate (as a percent)	1.00%
Change in fair value of ACRE Capital's MSRs outstanding due to increase (decrease) in weighted average discount rate	$ 1,800,000

Represents the number of loans held under mortgage servicing rights portfolio.

No definition available.

Name:	acre_NumberOfLoansHeldUnderMortgageServicingPortfolio
Namespace Prefix:	acre_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of changes in valuation inputs that would increase or decrease servicing assets fair value.

+ References

No definition available.

+ Details

Name:	acre_PercentageOfChangesInValuationInputsThatWouldIncreaseOrDecreaseServicingAssetFairValue
Namespace Prefix:	acre_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of decreases in the carrying value of servicing assets measured at fair value related to pre-payments and write-offs.

+ References

No definition available.

+ Details

Name:	acre_ServicingAssetAtFairValuePrepaymentsAndWriteOffs
Namespace Prefix:	acre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the unpaid principal balance amount on servicing assets.

+ References

No definition available.

+ Details

Name:	acre_ServicingAssetAtFairValueUnpaidPrincipalAmount
Namespace Prefix:	acre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The value of new servicing assets, subsequently measured at fair value, acquired or created during the current period through purchases or from transfers of financial assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 3

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Definition

The net increase or decrease in fair value as a result of changes in the inputs used to calculate the fair value of servicing assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Other net Increase or Decrease in the balance in servicing assets subsequently measured at fair value. This element is for changes other than additions, disposals, changes in fair value resulting from changes in valuation inputs or changes in assumptions, or other changes in fair value.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 3

-Subparagraph (a)(5)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122625-111746

+ Details

Name:	us-gaap_ServicingAssetAtFairValueOtherChangesThatAffectBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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