Line of Credit Covenant, Consolidated Recourse Indebtedness

No definition available.

Name:	ari_LineofCreditCovenantConsolidatedRecourseIndebtedness
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit, Covenant, Maximum Debt to Tangible Net Worth Ratio

+ References

No definition available.

+ Details

Name:	ari_LineofCreditCovenantMaximumDebttoTangibleNetWorthRatio
Namespace Prefix:	ari_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Covenant, Minimum EBITDA to Interest Expense Ratio

+ References

No definition available.

+ Details

Name:	ari_LineofCreditCovenantMinimumEBITDAtoInterestExpenseRatio
Namespace Prefix:	ari_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Covenant, Minimum Liquidity

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Covenant, Minimum Liquidity Percentage

+ References

No definition available.

+ Details

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

- Definition

Line of Credit, Covenant, Minimum Net Asset Value

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Covenant, Minimum Net Asset Value Percentage During Prior Quarter

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Covenant, Minimum Net Asset Value Percentage During Prior Year

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Covenant, Minimum Net Income

+ References

No definition available.

+ Details

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

- Definition

Line of Credit, Covenant, Minimum Shareholder's Equity of Gross Capital Proceeds

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Facility, Borrowing Margin Ratio

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Facility, Covenant Terms, Minimum Consolidated Tangible Net Worth Covenant, Amount

+ References

No definition available.

+ Details

Name:	ari_LineofCreditFacilityCovenantTermsMinimumConsolidatedTangibleNetWorthCovenantAmount
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Covenant Terms, Total Recourse Indebtedness, Amount

+ References

No definition available.

+ Details

Name:	ari_LineofCreditFacilityCovenantTermsTotalRecourseIndebtednessAmount
Namespace Prefix:	ari_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Covenant Terms, Total Recourse Indebtedness, Percent

+ References

No definition available.

+ Details

Name:	ari_LineofCreditFacilityCovenantTermsTotalRecourseIndebtednessPercent
Namespace Prefix:	ari_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Estimated Fair Value of Collateral Pledged Percentage

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Facility, Margin of Cash Borrowed, Percentage

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Facility, Period of Potential Extension

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Facility, Threshold Amount for Margin Calls

+ References

No definition available.

+ Details

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

- Definition

Line of Credit, Limited Guarantee Percentage Credit Facility

+ References

No definition available.

+ Details

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

- Definition

Number of Subsidiaries, Covenant Terms

+ References

No definition available.

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Borrowings - Additional Information (Details) (USD $)	9 Months Ended	12 Months Ended		1 Months Ended
Borrowings - Additional Information (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Aug. 31, 2010	Apr. 30, 2014	Jan. 31, 2010 subsidiary
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Basis spread on interest rate	4.40%
Line of Credit [Member]
Debt Instrument [Line Items]
Expiration period		3 years 2 months 12 days	3 years 3 months 12 days
Line of Credit [Member] \| Wells Fargo [Member]
Debt Instrument [Line Items]
Basis spread on interest rate		0.80%	1.05%
Expiration period		2 months 12 days	2 months 12 days
Line of Credit [Member] \| UBS [Member]
Debt Instrument [Line Items]
Maximum borrowing under facility				$ 133,899,000
Estimated fair value of collateral pledged, percentage				100.00%
Covenant terms, minimum net asset value				500,000,000
Covenant terms, maximum debt to tangible net worth ratio				3
Expiration period		3 years 8 months 12 days	4 years 8 months 12 days	4 years
Length of potential extension				1 year
Margin of cash borrowed, percentage				22.50%
Line of Credit [Member] \| UBS [Member] \| Six Month LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on interest rate				1.55%
Line of Credit [Member] \| JP Morgan Chase [Member]
Debt Instrument [Line Items]
Expiration period		0 years 1 month 6 days	1 year 1 month 6 days
Line of Credit [Member] \| JP Morgan Chase [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Basis spread on interest rate		2.50%
Wells Facility [Member] \| Line of Credit [Member] \| Wells Fargo [Member]
Debt Instrument [Line Items]
Maximum borrowing under facility					506,000,000
Basis spread on interest rate					1.50%
Threshold amount for margin calls					250,000
Covenant terms, minimum net asset value					100,000,000
Covenant terms, minimum net asset value percentage, during prior quarter					75.00%
Covenant terms, minimum net asset value percentage, during prior year					65.00%
Covenant terms, maximum debt to tangible net worth ratio					8
Covenant terms, minimum liquidity					2,500,000
Covenant terms, minimum EBITDA to interest expense ratio					1.5
Limited guarantee percentage credit facility					15.00%
Covenant terms, total recourse indebtedness, percent					10.00%
Covenant terms, total recourse indebtedness, amount					12,500,000
Wells Facility [Member] \| Line of Credit [Member] \| Wells Fargo [Member] \| Financial Guarantee [Member]
Debt Instrument [Line Items]
Maximum guarantee obligations					37,500,000
Wells Facility [Member] \| Line of Credit [Member] \| Wells Fargo [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Basis spread on interest rate					0.80%
Wells Facility [Member] \| Line of Credit [Member] \| Minimum [Member] \| Wells Fargo [Member]
Debt Instrument [Line Items]
Estimated fair value of collateral pledged, percentage					85.00%
Wells Facility [Member] \| Line of Credit [Member] \| Maximum [Member] \| Wells Fargo [Member]
Debt Instrument [Line Items]
Estimated fair value of collateral pledged, percentage					90.00%
DB Facility [Member] \| Line of Credit [Member] \| Deutsche Bank AG [Member]
Debt Instrument [Line Items]
Maximum borrowing under facility						300,005,000
Covenant terms, minimum shareholder's equity of gross capital proceeds		50.00%
DB Facility [Member] \| Line of Credit [Member] \| Minimum [Member] \| Deutsche Bank AG [Member]
Debt Instrument [Line Items]
Borrowing margin ratio						125.00%
DB Facility [Member] \| Line of Credit [Member] \| Minimum [Member] \| Deutsche Bank AG [Member] \| Three Month LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on interest rate						1.80%
DB Facility [Member] \| Line of Credit [Member] \| Maximum [Member] \| Deutsche Bank AG [Member]
Debt Instrument [Line Items]
Borrowing margin ratio						181.82%
DB Facility [Member] \| Line of Credit [Member] \| Maximum [Member] \| Deutsche Bank AG [Member] \| Three Month LIBOR [Member]
Debt Instrument [Line Items]
Basis spread on interest rate						2.32%
JP Morgan Facility [Member] \| Line of Credit [Member] \| JP Morgan Chase [Member]
Debt Instrument [Line Items]
Maximum borrowing under facility		175,000,000
Threshold amount for margin calls		250,000
Covenant terms, maximum debt to tangible net worth ratio		3
Covenant terms, total recourse indebtedness, percent		5.00%
Covenant terms, total recourse indebtedness, amount		15,000,000
Covenant terms, consolidated recourse indebtedness		12,500,000
Number of subsidiaries							2
Covenant terms, minimum consolidated tangible net worth		125,000,000
Covenant terms, minimum liquidity percentage		10.00%
Covenant terms, minimum net income		1
JP Morgan Facility [Member] \| Line of Credit [Member] \| JP Morgan Chase [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Basis spread on interest rate		2.50%
JP Morgan Facility [Member] \| Line of Credit [Member] \| Minimum [Member] \| JP Morgan Chase [Member]
Debt Instrument [Line Items]
Estimated fair value of collateral pledged, percentage		65.00%
JP Morgan Facility [Member] \| Line of Credit [Member] \| Maximum [Member] \| JP Morgan Chase [Member]
Debt Instrument [Line Items]
Estimated fair value of collateral pledged, percentage		90.00%