Business Combination, Consideration Transferred, Conversion Of Note Receivable [Member]

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- Definition

Business Combination, Consideration Transferred, Debt Assumed

+ References

No definition available.

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- Definition

Business Combination, Consideration Transferred and Debt Assumed

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- Definition

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings and Improvements

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No definition available.

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- Definition

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets

+ References

No definition available.

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- Definition

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Liabilities

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No definition available.

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- Definition

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets and Gain on Bargain Purchase

+ References

No definition available.

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- Definition

Change In Control Of Previously Unconsolidated (Consolidated) Investment, Gain On Change In Control

+ References

No definition available.

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- Definition

Existing Interest In previously Unconsolidated Investment

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No definition available.

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- Definition

The capitalized costs incurred during the period (excluded from amortization) to purchase, lease or otherwise acquire an unproved property, including costs of lease bonuses and options to purchase or lease properties, the portion of costs applicable to minerals when land including mineral rights is purchased in fee, brokers' fees, recording fees, legal costs, and other costs incurred in acquiring properties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10(c)(7)(ii))
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- Definition

The amount of expense recognized in the current period that reflects the allocation of capitalized costs associated with acquisition of business. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
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- 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.

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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-Paragraph 2
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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
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-Paragraph 7
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- References

No definition available.

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- Definition

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of real estate acquired, at the acquisition date.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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-Name Accounting Standards Codification
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- References

No definition available.

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Real Estate - Acquisitions and Conversions (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Business Acquisition [Line Items]
Purchase Price	$ 46,596		$ 254,532
Debt assumed	0		0
Capitalized acquisition costs	100
Acquisition costs expensed		$ 300
Purchase Price Allocation
Land	9,012		48,138
Buildings and improvements	34,064		173,576
Other assets	0		84
Acquisition-related intangible assets (in Acquired lease intangibles, net)	6,499		44,269
Acquisition-related intangible liabilities (in Acquired lease intangibles, net)	(2,979)		(11,535)
Net assets acquired	46,596		254,532
Consideration
Cash	46,171		200,429
Conversion of note receivable	0		41,010
Liabilities assumed	425		3,363
Existing interest in previously unconsolidated investment	0		4,159
Change in control of previously unconsolidated investment	0		5,571
Total Consideration	46,596		254,532
Core Portfolio
Business Acquisition [Line Items]
Purchase Price	1,337		42,800
Debt assumed	$ 0		$ 0
Acquisition costs expensed		200
Core Portfolio \| Bedford Green Land Parcel
Business Acquisition [Line Items]
Percent Acquired	100.00%
Purchase Price	$ 1,337
Debt assumed	0
Core Portfolio \| Market Square Shopping Center \| Wilmington, DE
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 42,800
Debt assumed			0
Funds Segment
Business Acquisition [Line Items]
Capitalized acquisition costs	100
Acquisition costs expensed		$ 100
Fund IV
Business Acquisition [Line Items]
Purchase Price			44,492
Debt assumed			$ 0
Fund IV \| Lincoln Place - Fairview Heights, IL \| Fairview Heights, IL
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 35,350
Debt assumed			$ 0
Fund IV \| Shaw's Plaza Waterville, ME \| Windham, ME
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 9,142
Debt assumed			0
Fund V
Business Acquisition [Line Items]
Purchase Price	45,259		167,240
Debt assumed	$ 0		$ 0
Fund V \| Trussville Promenade - Trussville, AL \| Trussville, AL
Business Acquisition [Line Items]
Percent Acquired	100.00%
Purchase Price	$ 45,259
Debt assumed	$ 0
Fund V \| Plaza Santa Fe - Santa Fe, NM \| Santa Fe, NM
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 35,220
Debt assumed			$ 0
Fund V \| Hickory Ridge - Hickory, NC \| Hickory, NC
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 44,020
Debt assumed			$ 0
Fund V \| New Towne Plaza - Canton, MI \| Canton, MI
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 26,000
Debt assumed			$ 0
Fund V \| Fairlane Green \| Allen Park, MI
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 62,000
Debt assumed			$ 0