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

Related Party Transaction, Amendment to Management Agreement, Real Estate Revenues Excluded from Net Income

No definition available.

Name:	acre_RelatedPartyTransactionAmendmentToManagementAgreementRealEstateRevenuesExcludedFromNetIncome
Namespace Prefix:	acre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the base management fees incurred as a percentage of stockholder's equity per annum.

No definition available.

Name:	acre_RelatedPartyTransactionBaseManagementFeesAsPercentageOfStockholdersEquityPerAnnum
Namespace Prefix:	acre_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the incentive fee payable on cumulative core earnings that are equal to or less than zero.

No definition available.

Name:	acre_RelatedPartyTransactionIncentiveFeePayableOnCumulativeCoreEarningsLessThanZero
Namespace Prefix:	acre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the minimum amount of cumulative core earnings which was used to calculate the incentive fee payable.

No definition available.

Name:	acre_RelatedPartyTransactionMinimumCumulativeCoreEarningsForCalculationOfIncentiveFee
Namespace Prefix:	acre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Related Party Transaction, Minimum Cumulative Core Earnings for Calculation of Incentive Fee, Number of Quarters

No definition available.

Name:	acre_RelatedPartyTransactionMinimumCumulativeCoreEarningsforCalculationofIncentiveFeeNumberofQuarters
Namespace Prefix:	acre_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Represents the percentage multiplied to arrive at difference of the first value which is affecting calculation of incentive fees.

No definition available.

Name:	acre_RelatedPartyTransactionPercentageMultipliedToArriveAtDifferenceOfFirstValueAffectingCalculationOfIncentiveFees
Namespace Prefix:	acre_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the percentage multiplied to arrive at the first value which is affecting calculation of incentive fees.

No definition available.

Name:	acre_RelatedPartyTransactionPercentageMultipliedToArriveAtFirstValueAffectingCalculationOfIncentiveFees
Namespace Prefix:	acre_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the period whose fiscal quarters is considered to arrive at the first value which is affecting the calculation of incentive fees.

No definition available.

Name:	acre_RelatedPartyTransactionPeriodWhoseFiscalQuartersIsConsideredToArriveAtSecondValueAffectingCalculationOfIncentiveFees
Namespace Prefix:	acre_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the previous period to calculate the product of weighted average price per share and weighted average number of shares of common stock and other shares.

No definition available.

Name:	acre_RelatedPartyTransactionPreviousPeriodForProductWeightedAveragePricePerShareAndWeightedAverageNumberOfSharesOfCommonStockAndOtherShares
Namespace Prefix:	acre_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the previous period for which core earnings are considered to arrive at the first value which is affecting calculation of incentive fees.

No definition available.

Name:	acre_RelatedPartyTransactionPreviousPeriodForWhichCoreEarningsIsConsideredToArriveAtFirstValueAffectingCalculationOfIncentiveFees
Namespace Prefix:	acre_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Related Party Transactions, Management Fee Look Back Period

No definition available.

Name:	acre_RelatedPartyTransactionsManagementFeeLookBackPeriod
Namespace Prefix:	acre_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Related Party Transactions, Management Fee Renewal Term

No definition available.

Name:	acre_RelatedPartyTransactionsManagementFeeRenewalTerm
Namespace Prefix:	acre_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Related Party Transactions, Termination Fee Based On Average Annual Management And Incentive Fees, Ratio

No definition available.

Name:	acre_RelatedPartyTransactionsTerminationFeeBasedOnAverageAnnualManagementAndIncentiveFeesRatio
Namespace Prefix:	acre_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Amount of contractual principal due at origination of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column F
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column F))
-URI http://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014

Name:	srt_MortgageLoansOnRealEstateFaceAmountOfMortgages
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(c))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

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

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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

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.

No definition available.

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

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentContinuingOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=acre_IncentiveFeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	us-gaap_RelatedPartyTransactionAxis=us-gaap_LoanPurchaseCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: