Common stock, dividends, per share, declared, period increase.

No definition available.

Name:	akr_CommonStockDividendsPerShareDeclaredPeriodIncrease
Namespace Prefix:	akr_
Data Type:	num:perShareItemType
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_ClassOfStockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_DividendPayableDateToBePaidDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the dividend to be paid was declared, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DividendsAxis=akr_RegularQuarterlyCashDividendMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DividendsAxis=akr_FourthQuarterTwoThousandEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DividendsAxis=akr_FirstQuarterTwoThousandNineteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Dividends and Distributions - Additional Information (Details) - $ / shares			3 Months Ended
	Feb. 28, 2019	Nov. 15, 2018	Mar. 31, 2019	Mar. 31, 2018
Class Of Stock [Line Items]
Cash dividends declared per common share (in dollars per share)			$ 0.28	$ 0.27
Regular Quarterly Cash Dividend
Class Of Stock [Line Items]
Cash dividends declared, period increase (in dollars per share)		$ 0.01
Cash dividends declared per common share (in dollars per share)	$ 0.28	$ 0.28
Fourth Quarter Two Thousand Eighteen
Class Of Stock [Line Items]
Cash dividends, declared date			Nov. 15, 2018
Cash dividends, record date			Dec. 31, 2018
Cash dividends, paid date			Jan. 15, 2019
First Quarter Two Thousand Nineteen
Class Of Stock [Line Items]
Cash dividends, declared date			Feb. 28, 2019
Cash dividends, record date			Mar. 29, 2019
Cash dividends, paid date			Apr. 15, 2019