Financing Receivable, Loan Specific, Credit Loss, Expense

No definition available.

Name:	ari_FinancingReceivableLoanSpecificCreditLossExpense
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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, Deferred Income, Unamortized Loan Commitment and Origination Fees, and Unamortized Discounts or Premiums, Period Increase

+ References

No definition available.

+ Details

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

- Definition

Loans and Leases Receivable, Deferred Income, Unrealized Gain On Foreign Currency Translation

+ References

No definition available.

+ Details

Name:	ari_LoansandLeasesReceivableDeferredIncomeUnrealizedGainOnForeignCurrencyTranslation
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, Gross, Paid-in-Kind Interest, Loan Commitment and Origination Fees, and Discounts or Premiums, Amortization

+ References

No definition available.

+ Details

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

- Definition

Loans and Leases Receivable, Net, Deferred Income, PIK Interest, Loan Commitment and Origination Fees, and Discounts or Premiums, Amortization

+ References

No definition available.

+ Details

Name:	ari_LoansandLeasesReceivableNetDeferredIncomePIKInterestLoanCommitmentandOriginationFeesandDiscountsorPremiumsAmortization
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

Payments to Purchase Loans Held-for-sale, Add-on Funding

+ References

No definition available.

+ Details

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

- Definition

Real Estate Owned, Transfer To Real Estate Owned, Held For Sale, Deferred Fees and Other Items

+ References

No definition available.

+ Details

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

- Definition

Real Estate Owned, Transfer To Real Estate Owned, Held For Sale, Gross

+ References

No definition available.

+ Details

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

- Definition

Real Estate Owned, Transfer To Real Estate Owned, Held For Sale, Net

+ References

No definition available.

+ Details

Name:	ari_RealEstateOwnedTransferToRealEstateOwnedHeldForSaleNet
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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=123605502&loc=d3e21338-158488

+ 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

+ 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/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=6378536&loc=d3e10095-111533

+ 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, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3B
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447

+ Details

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

- Definition

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.

+ References

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 https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

+ Details

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

- Definition

Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121611286&loc=d3e11927-110247

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82919202-210446

+ Details

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

- Definition

The amount of cash paid for the origination of mortgages that are held for sale.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3536-108585

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3461-108585

+ Details

Name:	us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from collection of repayments from borrowers on loans that are secured with real estate mortgages and are held with the intention to resell in the near future.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3461-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 16
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3337-108585

+ Details

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

- 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 - Activity Relating to Loan Investment Portfolio (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Aug. 03, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Principal Balance
Principal value, beginning balance	$ 7,890,848
Principal value, ending balance	8,753,291
Specific CECL Allowance
Specific provision for loan loss, beginning	(145,000)
Specific provision for loan loss, ending	(119,000)
Carry Value, Net
Transfer to real estate owned, held for sale	156,201	$ 0
General CECL allowance	(21,985)					$ (33,588)
Carrying value, net	8,731,306		$ 226,500			7,857,260
General CECL Allowance on unfunded commitments	2,812	2,193		$ 3,999	$ 3,928	3,106	$ 2,444	$ 3,794	$ 3,365
Commercial Mortgage and Subordinated Portfolio Segment
Principal Balance
Principal value, beginning balance	8,072,377
New funding of loans	2,753,609
Add-on loan fundings	493,027
Loan repayments and sales	(1,511,311)
Gain (loss) on foreign currency translation	(675,007)
Transfer to real estate owned	(225,036)
PIK interest and amortization of fees	16,149
Principal value, ending balance	8,923,808
Deferred Fees/Other Items
Deferred fees/other items, beginning	(36,529)
Gain (loss) on foreign currency translation	6,425
Transfer to real estate owned	(1,423)
Deferred fees and other items	(42,779)
PIK interest and amortization of fees	22,789
Deferred fees/other items, ending	(51,517)
Specific CECL Allowance
Specific provision for loan loss, beginning	(145,000)	(175,000)
Specific provision for loan loss, ending	(119,000)	$ (145,000)
Carry Value, Net
Carrying value, beginning balance	7,890,848
New funding of loans	2,753,609
Add-on loan fundings	493,027
Loan repayments and sales	(1,511,311)
Gain (loss) on foreign currency translation	(668,582)
Specific CECL Allowance, net	26,000
Transfer to real estate owned, held for sale	(226,459)
Deferred fees and other items	(42,779)
PIK interest and amortization of fees	38,938
Carrying value, ending balance	8,753,291
Carrying value, net	$ 206,800					$ 97,800