ACQUISITIONS AND DISPOSITIONS (Narrative, Acquisitions) (Details) $ in Thousands	Dec. 30, 2019 USD ($) ft² a building	Sep. 07, 2018 USD ($) a ft² building	Jun. 08, 2018 USD ($) a extention_option	Dec. 31, 2020 ft²	Dec. 31, 2019 a
Payments to acquire real estate	$ 584,300
Leasing commission	$ 19,319
The Woodlands Warehouse
Square footage of building | ft²	125,801
Waterway Land
Area of land | a	9.3
Payments to acquire real estate	$ 565,000
Century Park
Asset acquisition, number of buildings acquired | building	17
Square footage of building | a					1,302,597
Area of land | a	63
The Woodlands Towers at the Waterway
Square footage of building | ft²	805,993			595,618
The Woodlands Towers at the Waterway and The Woodlands Warehouse
Duration of lease	13 years
Lakefront North
Area of land | a		12.9
Payments to acquire real estate		$ 53,000
Number of buildings | building		2
Area of real estate property | ft²		258,000
250 Water Street
Area of land purchased | a			1
Purchase price of land acquired			$ 180,000
Payments to acquire land			53,100
250 Water Street | Notes Payable, Other Payables
Short-term debt			$ 129,700
Interest free term			6 months
Number of extension options | extention_option			3
Extension option, term			6 months
Interest rate (as a percent)			6.00%
The Woodlands Towers at the Waterway
Asset acquisition, number of buildings acquired | building	2
Square footage of building | ft²	1,401,611
Leasing commission	$ 18,599