REAL ESTATE PROPERTIES REAL ESTATE PROPERTIES 2 (Details)		12 Months Ended
		Dec. 31, 2018 USD ($) ft²	Dec. 31, 2017 USD ($) ft²	Dec. 31, 2016 USD ($) ft²
Sales of real estate properties [Line Items]
Net Sales Price of Real Estate Sold		$ 22,004,000	$ 37,557,000	$ 73,725,000
Basis		7,731,000	15,702,000	31,555,000
Gain, net of loss, on Sales of Real Estate Investments		$ 14,273,000	$ 21,855,000	$ 42,170,000
World Houston International Business Ctr 18 [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²		33,000
Date Of Property Sale		1/26/18
Net Sales Price of Real Estate Sold		$ 2,289,000
Basis		1,211,000
Gain, net of loss, on Sales of Real Estate Investments		$ 1,078,000
56th Street Commerce Park [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²		181,000
Date Of Property Sale		3/20/18
Net Sales Price of Real Estate Sold		$ 12,032,000
Basis		2,888,000
Gain, net of loss, on Sales of Real Estate Investments		$ 9,144,000
35th Avenue Distribution Center [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²		125,000
Date Of Property Sale		7/26/18
Net Sales Price of Real Estate Sold		$ 7,683,000
Basis		3,632,000
Gain, net of loss, on Sales of Real Estate Investments		4,051,000
Stemmons Circle [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²			99,000
Date Of Property Sale			5/12/17
Net Sales Price of Real Estate Sold			$ 5,051,000
Basis			1,329,000
Gain, net of loss, on Sales of Real Estate Investments			$ 3,722,000
Techway Southwest I, II, III, & IV [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²			415,000
Date Of Property Sale			6/19/17
Net Sales Price of Real Estate Sold			$ 32,506,000
Basis			14,373,000
Gain, net of loss, on Sales of Real Estate Investments			18,133,000
Northwest Point Distribution and Service Centers [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				232,000
Date Of Property Sale				2/12/16
Net Sales Price of Real Estate Sold				$ 15,189,000
Basis				5,080,000
Gain, net of loss, on Sales of Real Estate Investments				$ 10,109,000
North Stemmons III [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				60,000
Date Of Property Sale				3/4/16
Net Sales Price of Real Estate Sold				$ 3,131,000
Basis				1,908,000
Gain, net of loss, on Sales of Real Estate Investments				$ 1,223,000
North Stemmons II [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				26,000
Date Of Property Sale				4/12/16
Net Sales Price of Real Estate Sold				$ 1,203,000
Basis				765,000
Gain, net of loss, on Sales of Real Estate Investments				$ 438,000
Lockwood Distribution Center [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				392,000
Date Of Property Sale				4/18/16
Net Sales Price of Real Estate Sold				$ 14,024,000
Basis				4,154,000
Gain, net of loss, on Sales of Real Estate Investments				$ 9,870,000
West Loop Distribution Center 1 & 2 [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				161,000
Date Of Property Sale				4/19/16
Net Sales Price of Real Estate Sold				$ 13,154,000
Basis				3,564,000
Gain, net of loss, on Sales of Real Estate Investments				$ 9,590,000
America Plaza [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				121,000
Date Of Property Sale				4/28/16
Net Sales Price of Real Estate Sold				$ 7,938,000
Basis				3,378,000
Gain, net of loss, on Sales of Real Estate Investments				$ 4,560,000
Interstate Commons Distribution Center I and II [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				142,000
Date Of Property Sale				5/31/16
Net Sales Price of Real Estate Sold				$ 9,906,000
Basis				3,568,000
Gain, net of loss, on Sales of Real Estate Investments				$ 6,338,000
Castilian Research Center [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²	[1]			30,000
Date Of Property Sale	[1]			6/28/16
Net Sales Price of Real Estate Sold	[1]			$ 7,698,000
Basis	[1]			7,513,000
Gain, net of loss, on Sales of Real Estate Investments	[1]			$ 185,000
Memphis I [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²				92,000
Date Of Property Sale				12/16/16
Net Sales Price of Real Estate Sold				$ 1,482,000
Basis				1,625,000
Gain, net of loss, on Sales of Real Estate Investments				(143,000)
Land [Member]
Sales of real estate properties [Line Items]
Proceeds from Sale of Property, Plant, and Equipment		2,577,000	3,778,000	5,400,000
Gain on sales of land		$ 86,000	$ 293,000	$ 733,000
Castilian Research Center [Member]
Sales of real estate properties [Line Items]
Less Than Wholly Owned Joint Venture Investment Ownership Percentage				80.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners				20.00%

[1] EastGroup owned 80% of Castilian Research Center through a joint venture. The information shown for this transaction also includes the 20% attributable to the Company's noncontrolling interest partner.