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

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 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	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Principal Balance
Principal value, beginning balance	$ 7,134,992
New loan fundings	460,452	$ 0
Principal value, ending balance	7,721,798
Specific CECL Allowance
Specific provision for loan loss, beginning	(30,836)
Specific provision for loan loss, ending	(34,712)
Carry Value, Net
Payments to Fund Commercial Mortgage Loans	460,452	0
General CECL allowance	(34,712)		$ (30,836)
Carrying value, net	7,728,286		$ 7,145,356
Commercial Mortgage and Subordinated Portfolio Segment
Principal Balance
Principal value, beginning balance	7,550,410
New loan fundings	460,452
Add-on loan fundings	72,867
Loan repayments and sale	(93,400)
Gain (loss) on foreign currency translation	148,405
Principal value, ending balance	8,138,734
Deferred Fees/Other Items
Deferred fees/other items, beginning	(31,718)
Gain (loss) on foreign currency translation	(503)
Deferred fees and other items	(6,854)
Amortization of fees	5,839
Deferred fees/other items, ending	(33,236)
Specific CECL Allowance
Specific provision for loan loss, beginning	(342,500)	(193,000)
Specific provision for loan loss, ending	(342,500)	$ (335,000)
Carry Value, Net
Carrying value, beginning balance	7,176,192
Payments to Fund Commercial Mortgage Loans	460,452
Add-on loan fundings	72,867
Loan repayments	(93,400)
Gain (loss) on foreign currency translation	147,902
Deferred fees and other items	(6,854)
Amortization of fees	5,839
Carrying value, ending balance	$ 7,762,998