SCHEDULE IV - MORTGAGE LOANS ON REAL ESTATE - Loans On Real Estate (Details) $ in Thousands	Dec. 31, 2016 USD ($) loan	Dec. 31, 2015 USD ($)
Mortgage Loans on Real Estate [Line Items]
Face Amount of Notes Receivable	$ 272,200
Net carrying amount of notes receivable	$ 276,163	$ 147,188
Number of nonperforming loans \| loan	1
Nonperforming note	$ 12,000
First Mortgage Loan, 6.0% Loan, Due 4/28/2017
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	6.00%
Face Amount of Notes Receivable	$ 9,000
Net carrying amount of notes receivable	$ 9,000
First Mortgage Loan, 6.0% Loan Due 5/1/2017
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	6.00%
Face Amount of Notes Receivable	$ 15,000
Net carrying amount of notes receivable	$ 15,000
Mezzanine Loan 18.0% Loan Due 7/1/2017
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	18.00%
Face Amount of Notes Receivable	$ 3,007
Net carrying amount of notes receivable	$ 4,506
First Mortgage Loan LIBOR Plus 7.1% Due 6/252018
Mortgage Loans on Real Estate [Line Items]
Basis spread on variable rate	7.10%
Face Amount of Notes Receivable	$ 26,000
Net carrying amount of notes receivable	$ 26,000
First Mortgage Loan, 8.1% Loan, Due 2019 [Member]
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	8.10%
Face Amount of Notes Receivable	$ 153,400
Net carrying amount of notes receivable	$ 153,400
Preferred Equity, 8.7% Loan, Due 9/9/2019
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	8.70%
Face Amount of Notes Receivable	$ 10,000
Net carrying amount of notes receivable	$ 10,000
Zero Coupon Loan Due 5/31/2020
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	2.50%
Face Amount of Notes Receivable	$ 29,793
Net carrying amount of notes receivable	$ 31,007
Preferred Equity, 15.3% Loan, Due 2/3/2021
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	15.30%
Face Amount of Notes Receivable	$ 14,000
Net carrying amount of notes receivable	$ 15,250
First Mortgage Loan, 9.0% Loan Due On Demand
Mortgage Loans on Real Estate [Line Items]
Effective Interest Rate	9.00%
Face Amount of Notes Receivable	$ 12,000
Net carrying amount of notes receivable	$ 12,000

Mortgage Loans on Real Estate, Number of Loans, Nonperforming

No definition available.

Name:	akr_MortgageLoansonRealEstateNumberofLoansNonperforming
Namespace Prefix:	akr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5111-111524

+ Details

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

- Definition

The percentage points (also referred to as 'margin') added to the reference rate as stated in the loan agreement and used to compute the variable rate on the loans receivable. For instance, the loan agreement might state that the interest rate the borrower is obligated to pay is the London Interbank Offered Rate (LIBOR) plus three quarters (3/4) of a percentage point adjusted quarterly (each three months). LIBOR in this example is the index or reference rate, 3/4 percentage point is the margin, the reference rate plus the margin is the fully indexed rate. This element would be used to report separately the margin.

+ References

No definition available.

+ Details

Name:	us-gaap_LoansReceivableBasisSpreadOnVariableRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The carrying amount of the outstanding balance due under the mortgage loan.

+ References

Reference 1: 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 2: 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

+ Details

Name:	us-gaap_MortgageLoansOnRealEstateCarryingAmountOfMortgages
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

+ Details

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

- Definition

The stated interest rate on the mortgage loan receivable or the weighted average interest rate on a group of loans.

+ References

+ Details

Name:	us-gaap_MortgageLoansOnRealEstateInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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_MortgageLoansOnRealEstateLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_FirstMortgageLoan6.0LoanDue4282017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_MezzanineLoan18.0LoanDue712017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_FirstMortgageLoanLIBORPlusSevenPointOnePercentDue2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_FirstMortgageLoan8.1LoanDue2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_PreferredEquity8.0LoanDue2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_ZeroCouponLoanDue2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_PreferredEquity15.3LoanDue2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=akr_FirstMortgageLoanSevenPointSevenPercentLoanDue2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: