Available-for-sale Debt Securities, Face Amount

No definition available.

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

- Definition

Mortgage Loans, Option to Extend Loan Agreement, Term

+ References

No definition available.

+ Details

Name:	ari_MortgageLoansOptiontoExtendLoanAgreementTerm
Namespace Prefix:	ari_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Mortgage Loans, Term of Loan

+ References

No definition available.

+ Details

Name:	ari_MortgageLoansTermofLoan
Namespace Prefix:	ari_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Mortgage Loans on Real Estate, Area of Real Estate Property

+ References

No definition available.

+ Details

Name:	ari_MortgageLoansonRealEstateAreaofRealEstateProperty
Namespace Prefix:	ari_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Mortgage Loans on Real Estate, Loan to Value Ratio

+ References

No definition available.

+ Details

Name:	ari_MortgageLoansonRealEstateLoantoValueRatio
Namespace Prefix:	ari_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Mortgage Loans on Real Estate, Number of Units in Real Estate Property

+ References

No definition available.

+ Details

Name:	ari_MortgageLoansonRealEstateNumberofUnitsinRealEstateProperty
Namespace Prefix:	ari_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Options to Extend Loan Agreement

+ References

No definition available.

+ Details

Name:	ari_NumberofOptionstoExtendLoanAgreement
Namespace Prefix:	ari_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Proceeds from Sale of Available-for-sale Securities, Debt, Net of Repayment of Line of Credit

+ References

No definition available.

+ Details

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

- Definition

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

+ Details

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

- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

+ Details

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

- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

+ Details

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

- Definition

Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Mortgage-Backed Securities
-URI http://asc.fasb.org/extlink&oid=6517959

+ Details

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

- Definition

Amount of the contractual principal due at the origination of the mortgage loan (face amount).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph c
-Subparagraph Schedule IV
-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 29
-Article 12

+ Details

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

- Definition

The aggregate amount of the participating mortgage obligation at the end of the accounting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=29639217&loc=d3e10013-112621

+ Details

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

- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

+ References

No definition available.

+ Details

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

- Definition

The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	invest_InvestmentHoldingAxis=ari_CMBSUBSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=us-gaap_FirstMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_HotelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateLoanTypeAxis=ari_SubordinateMortgageLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ari_HotelArubaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ParticipatingMortgageLoansAxis=ari_SeniorParticipationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ParticipatingMortgageLoansAxis=ari_JuniorParticipationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=ari_WellsFargoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt Securities - Additional Information (Details)	1 Months Ended					3 Months Ended								12 Months Ended
Debt Securities - Additional Information (Details)	Feb. 28, 2015 USD ($)	May. 31, 2014 USD ($) timeshare_unit	May. 31, 2014 USD ($) casino	May. 31, 2014 USD ($) room	May. 31, 2014 USD ($) ft²	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) option	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Oct. 31, 2015 USD ($)	Aug. 31, 2014 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Realized gain (loss) on sale of securities						$ 0	$ 0	$ 0	$ (443,000)	$ 0	$ 0	$ 0	$ 0	$ (443,000)	$ 0	$ 0
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost of debt securities sold	$ 24,038,000									17,783,000					17,783,000
Realized gain (loss) on sale of securities	(443,000)
Realized gain on sale of debt securities	43,000
Realized loss on sale of debt securities	486,000
Reclassification out of accumulated other comprehensive income	678,000
Proceeds from sale of debt securities, net of debt facility repayment	1,341,000
Available-for-sale securities, face amount										17,013,000					17,013,000
Commercial Mortgage Backed Securities [Member] \| CMBS - UBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, face amount										387,100,000					387,100,000
Aggregate purchase price of CMBS										375,006,000					375,006,000
First Mortgage [Member]
Schedule of Available-for-sale Securities [Line Items]
Original Face Amount								$ 33,000,000
Hotel [Member] \| First Mortgage [Member]
Schedule of Available-for-sale Securities [Line Items]
Original Face Amount																	$ 227,000,000
Subordinate Loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Original Face Amount						$ 964,955,000				$ 562,434,000				$ 964,955,000	$ 562,434,000
Subordinate Loans [Member] \| Hotel [Member] \| Hotel - Aruba [Member]
Schedule of Available-for-sale Securities [Line Items]
Property Size, Number of Units/Rooms		114	2	442
Property Size, Area \| ft²					131,500
Term of loan														3 years
Number of options to extend loan agreement \| option														2
Option to extend loan agreement, term														1 year
Appraised loan to value ratio														60.00%
Subordinate Loans [Member] \| Hotel [Member] \| Hotel - Aruba [Member] \| First Mortgage [Member]
Schedule of Available-for-sale Securities [Line Items]
Original Face Amount		$ 155,000,000	$ 155,000,000	$ 155,000,000	$ 155,000,000
Senior Participation [Member] \| Subordinate Loans [Member] \| Hotel [Member] \| Hotel - Aruba [Member]
Schedule of Available-for-sale Securities [Line Items]
Participations sold												90,000,000						$ 90,000,000
Junior Participation [Member] \| Subordinate Loans [Member] \| Hotel [Member] \| Hotel - Aruba [Member]
Schedule of Available-for-sale Securities [Line Items]
Participations sold												$ 65,000,000						$ 65,000,000
Line of Credit [Member] \| Wells Fargo [Member]
Schedule of Available-for-sale Securities [Line Items]
Repayments of debt facility	$ 22,254,000