REAL ESTATE PROPERTIES REAL ESTATE PROPERTIES 2 (Details)		12 Months Ended
		Dec. 31, 2019 USD ($) ft² a	Dec. 31, 2018 USD ($) ft²	Dec. 31, 2017 USD ($) ft²
Sales of real estate properties [Line Items]
Net Sales Price of Real Estate Sold		$ 66,559,000	$ 22,004,000	$ 37,557,000
Basis		25,491,000	7,731,000	15,702,000
Gain on Sales of Real Estate Investments		$ 41,068,000	$ 14,273,000	$ 21,855,000
World Houston International Business Ctr 5 [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²		51,000
Date Of Property Sale		Jan. 29, 2019
Net Sales Price of Real Estate Sold		$ 3,679,000
Basis		(1,354,000)
Gain on Sales of Real Estate Investments		$ 2,325,000
Altamonte Commerce Center [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²		186,000
Date Of Property Sale		May 20, 2019
Net Sales Price of Real Estate Sold		$ 14,423,000
Basis		5,342,000
Gain on Sales of Real Estate Investments		$ 9,081,000
University Business Center 130 [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²	[1]	40,000
Date Of Property Sale	[1]	Nov. 07, 2019
Net Sales Price of Real Estate Sold	[1]	$ 11,083,000
Basis	[1]	2,729,000
Gain on Sales of Real Estate Investments	[1]	$ 8,354,000
Southpointe Distribution Center [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²		207,000
Date Of Property Sale		Dec. 03, 2019
Net Sales Price of Real Estate Sold		$ 13,699,000
Basis		(2,281,000)
Gain on Sales of Real Estate Investments		$ 11,418,000
University Business Center 125 and 175 [Member]
Sales of real estate properties [Line Items]
Size (in square feet) of property sold | ft²		133,000
Date Of Property Sale		Dec. 11, 2019
Net Sales Price of Real Estate Sold		$ 23,675,000
Basis		(13,785,000)
Gain on Sales of Real Estate Investments		$ 9,890,000
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			Jan. 26, 2018
Net Sales Price of Real Estate Sold			$ 2,289,000
Basis			1,211,000
Gain 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			Mar. 20, 2018
Net Sales Price of Real Estate Sold			$ 12,032,000
Basis			2,888,000
Gain 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			Jul. 26, 2018
Net Sales Price of Real Estate Sold			$ 7,683,000
Basis			3,632,000
Gain 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				May 12, 2017
Net Sales Price of Real Estate Sold				$ 5,051,000
Basis				1,329,000
Gain 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				Jun. 19, 2017
Net Sales Price of Real Estate Sold				$ 32,506,000
Basis				14,373,000
Gain on Sales of Real Estate Investments				18,133,000
Land [Member]
Sales of real estate properties [Line Items]
SIze (in acres) of land sold | a		0.2
Proceeds from Sale of Property, Plant, and Equipment		$ 185,000	2,577,000	3,778,000
Gain on sales of land		$ 83,000	$ 86,000	$ 293,000
University Business Center 130 [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 University Business Center 130 through a joint venture. The information shown for this transaction also includes the 20% attributable to the Company's noncontrolling interest partner.