Real Estate Investments Business Acquisitions (Details) shares in Thousands, $ in Thousands		3 Months Ended
	Mar. 01, 2017 USD ($) property shares	Mar. 31, 2018 USD ($) shares	Mar. 31, 2017 USD ($)
Business Acquisition [Line Items]
Purchase Price		$ 123,230	$ 9,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		$ 9,700	0
Parent Company [Member]
Business Acquisition [Line Items]
Conversion of Stock, Conversion Ratio		0.45
Shares of common stock issued for merger (in shares) | shares		65,500
Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Intangible assets		$ 9,929	0
Off-Market Lease, Unfavorable [Member]
Business Acquisition [Line Items]
Intangible assets		$ 6,123	$ 0
Ballard Blocks I [Member]
Business Acquisition [Line Items]
Date Purchased		Jan. 02, 2018
Property Name		Ballard in Blocks I
City/State		Seattle, WA
Business Acquisition, Percentage of Voting Interests Acquired		49.90%
Purchase Price		$ 54,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		0
Ballard Blocks I [Member] | Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Intangible assets		3,668
Ballard Blocks I [Member] | Off-Market Lease, Unfavorable [Member]
Business Acquisition [Line Items]
Intangible assets		$ 2,350
Ballard Blocks II [Member]
Business Acquisition [Line Items]
Date Purchased		Jan. 02, 2018
Property Name		Ballard in Blocks II
City/State		Seattle, WA
Business Acquisition, Percentage of Voting Interests Acquired		49.90%
Purchase Price		$ 4,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		0
Ballard Blocks II [Member] | Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Intangible assets		0
Ballard Blocks II [Member] | Off-Market Lease, Unfavorable [Member]
Business Acquisition [Line Items]
Intangible assets		$ 0
Metuchen [Member]
Business Acquisition [Line Items]
Date Purchased		Jan. 05, 2018
Property Name		Metuchen
City/State		Metuchen, NJ
Business Acquisition, Percentage of Voting Interests Acquired		20.00%
Purchase Price		$ 33,830
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		0
Metuchen [Member] | Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Intangible assets		3,147
Metuchen [Member] | Off-Market Lease, Unfavorable [Member]
Business Acquisition [Line Items]
Intangible assets		$ 1,905
Hewlett Crossing I & II [Member]
Business Acquisition [Line Items]
Date Purchased		Jan. 10, 2018
Property Name		Hewlett Crossing I & II
City/State		Hewlett, NY
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Purchase Price		$ 30,900
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		9,700
Hewlett Crossing I & II [Member] | Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Intangible assets		3,114
Hewlett Crossing I & II [Member] | Off-Market Lease, Unfavorable [Member]
Business Acquisition [Line Items]
Intangible assets		$ 1,868
The Field at Commonwealth [Member]
Business Acquisition [Line Items]
Date Purchased			Mar. 06, 2017
Property Name			The Field at Commonwealth
City/State			Chantilly, VA
Business Acquisition, Percentage of Voting Interests Acquired			100.00%
Purchase Price			$ 9,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			0
The Field at Commonwealth [Member] | Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Intangible assets			0
The Field at Commonwealth [Member] | Off-Market Lease, Unfavorable [Member]
Business Acquisition [Line Items]
Intangible assets			$ 0
Pinecrest Place [Member] [Member]
Business Acquisition [Line Items]
Date Purchased			Mar. 08, 2017
Property Name			Pinecrest Place (1)
City/State			Miami, FL
Business Acquisition, Percentage of Voting Interests Acquired			100.00%
Purchase Price			$ 0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			0
Pinecrest Place [Member] [Member] | Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Intangible assets			0
Pinecrest Place [Member] [Member] | Off-Market Lease, Unfavorable [Member]
Business Acquisition [Line Items]
Intangible assets			$ 0
Equity One Inc. [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	$ 1,383,291
Intangible assets	$ 458,877
Shares of common stock issued for merger (in shares) | shares	65,379
Number of real estate properties acquired | property	121
Equity One Inc. [Member] | Partially Owned Properties [Member]
Business Acquisition [Line Items]
Number of real estate properties acquired | property	8