Financing receivable, excluding accrued interest, after specific allowance for credit loss.

No definition available.

Name:	ari_FinancingReceivableExcludingAccruedInterestAfterSpecificAllowanceForCreditLoss
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Increase in Specific CECL Allowance, net.

+ References

No definition available.

+ Details

Name:	ari_FinancingReceivableLoanIncreaseToSpecificCreditLossAllowanceNet
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loan portfolio deferred fee amortization.

+ References

No definition available.

+ Details

Name:	ari_LoanPortfolioDeferredFeeAmortization
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loan portfolio deferred fees other items.

+ References

No definition available.

+ Details

Name:	ari_LoanPortfolioDeferredFeesOtherItems
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loan portfolio deferred gain loss foreign currency translation.

+ References

No definition available.

+ Details

Name:	ari_LoanPortfolioDeferredGainLossForeignCurrencyTranslation
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loan and Leases Receivable, Deferred income [Roll Forward]

+ References

No definition available.

+ Details

Name:	ari_LoanandLeasesReceivableDeferredincomeRollForward
Namespace Prefix:	ari_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Loan and Leases Receivable, Gross [Roll Forward]

+ References

No definition available.

+ Details

Name:	ari_LoanandLeasesReceivableGrossRollForward
Namespace Prefix:	ari_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Loan and Leases Receivable, Net [Roll Forward]

+ References

No definition available.

+ Details

Name:	ari_LoanandLeasesReceivableNetRollForward
Namespace Prefix:	ari_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Loans and leases receivable deferred loss on sale.

+ References

No definition available.

+ Details

Name:	ari_LoansAndLeasesReceivableDeferredLossOnSale
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loans and Leases Receivable, Gain (Loss) on Sales, Gross

+ References

No definition available.

+ Details

Name:	ari_LoansAndLeasesReceivableGainLossOnSalesGross
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loans and leases receivable gross transfer to other assets.

+ References

No definition available.

+ Details

Name:	ari_LoansAndLeasesReceivableGrossTransferToOtherAssets
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loans and Leases Receivable, Net, Realized Gain (Loss) On Investment

+ References

No definition available.

+ Details

Name:	ari_LoansAndLeasesReceivableNetRealizedGainLossOnInvestment
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loans and leases receivable net transfer to other assets.

+ References

No definition available.

+ Details

Name:	ari_LoansAndLeasesReceivableNetTransferToOtherAssets
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loans and Leases Receivable, Deferred Income, Amortization

+ References

No definition available.

+ Details

Name:	ari_LoansandLeasesReceivableDeferredIncomeAmortization
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loans and Leases Receivable, Deferred Income, Period Increase

+ References

No definition available.

+ Details

Name:	ari_LoansandLeasesReceivableDeferredIncomePeriodIncrease
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Loans and Leases Receivable, Gross, Foreign Currency Gain (Loss)

+ References

No definition available.

+ Details

Name:	ari_LoansandLeasesReceivableGrossForeignCurrencyGainLoss
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loans and Leases Receivable, Net, Foreign Currency Gain (Loss)

+ References

No definition available.

+ Details

Name:	ari_LoansandLeasesReceivableNetForeignCurrencyGainLoss
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Mortgage Loans on Real Estate, Commercial and Consumer And Financing Receivable, Net

+ References

No definition available.

+ Details

Name:	ari_MortgageLoansOnRealEstateCommercialAndConsumerAndFinancingReceivableNet
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Payments to fund commercial mortgage loans.

+ References

No definition available.

+ Details

Name:	ari_PaymentsToFundCommercialMortgageLoans
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Payments to purchase loans add on fundings.

+ References

No definition available.

+ Details

Name:	ari_PaymentsToPurchaseLoansAddOnFundings
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Proceeds from collection of mortgage loans.

+ References

No definition available.

+ Details

Name:	ari_ProceedsFromCollectionOfMortgageLoans
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

+ References

No definition available.

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of fee received for commitment to originate or purchase financing receivable where likelihood of commitment being exercised is remote, to be recognized as service income.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481598/310-20-45-2

+ Details

Name:	us-gaap_FinancingReceivableDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

+ Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=ari_CommercialMortgageandSubordinatedPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commercial Mortgage Loans, Subordinate Loans and Other Lending Assets, Net - Schedule of Activity Relating to Loan Portfolio (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Principal Balance
Principal value, beginning balance	$ 8,384,575
New loan fundings	955,328	$ 181,017
Principal value, ending balance	7,864,803
Specific CECL Allowance
Specific provision for loan loss, beginning	(26,482)
Specific provision for loan loss, ending	(34,192)
Carry Value, Net
Valuation allowance, loan held for sale	(128,191)	(86,604)
General CECL allowance	(34,192)		$ (26,482)
Carrying value, net	7,830,611		$ 8,358,093
Commercial Mortgage and Subordinated Portfolio Segment
Principal Balance
Principal value, beginning balance	8,610,110
New loan fundings	955,328
Add-on loan fundings	530,747
Loan repayments and sale	(1,711,682)
Gain (loss) on foreign currency translation	155,874
Transfer to Other Assets	(159,667)
Valuation allowance, loan held for sale	(137,312)
Principal value, ending balance	8,243,398
Deferred Fees/Other Items
Deferred fees/other items, beginning	(32,535)
Gain (loss) on foreign currency translation	(825)
Valuation allowance, loan held for sale	9,121
Deferred fees and other items	(34,468)
Amortization of fees	22,612
Deferred fees/other items, ending	(36,095)
Specific CECL Allowance
Specific provision for loan loss, beginning	(193,000)	(133,500)
Increase in Specific CECL Allowance, net	(149,500)
Specific provision for loan loss, ending	(342,500)	$ (193,000)
Carry Value, Net
Carrying value, beginning balance	8,384,575
Add-on loan fundings	530,747
Loan repayments	(1,711,682)
Gain (loss) on foreign currency translation	155,049
Transfer to Other Assets	(159,667)
Valuation allowance, loan held for sale	(128,191)
Deferred fees and other items	(34,468)
Amortization of fees	22,612
Carrying value, ending balance	$ 7,864,803