ACQUISITIONS AND DISPOSITIONS (Narrative) (Details)											3 Months Ended								6 Months Ended	10 Months Ended	12 Months Ended
	Dec. 30, 2019 USD ($) ft² a building	Dec. 20, 2019 USD ($)	Oct. 29, 2019 USD ($) a	Sep. 16, 2019 USD ($) ft² a	Sep. 07, 2018 USD ($) ft² a building	Jun. 08, 2018 USD ($) a extention_option	Dec. 28, 2017 USD ($)	Mar. 01, 2017 USD ($)	Jan. 18, 2017 USD ($) a	Jan. 06, 2017 USD ($) a	Dec. 31, 2019 USD ($) ft²	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) item	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($) ft²	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Area of land | a					12.9
Payments to acquire real estate	$ 584,300,000				$ 53,000,000.0
Leasing commission	$ 19,319,000
Equity in earnings from real estate and other affiliates																					$ 30,629,000	$ 39,954,000	$ 25,498,000
Gain (loss) on sale or disposal of real estate and other assets, net																					22,362,000	(4,000)	55,235,000
Proceeds from sales of properties																					67,110,000	0	88,384,000
Number of buildings | building					2
Area of real estate property | ft²					258,000
Revenues since the acquisition date											$ 284,161,000	$ 231,172,000	$ 431,316,000	$ 353,890,000	$ 464,693,000	$ 257,160,000	$ 181,005,000	$ 161,679,000			1,300,539,000	1,064,537,000	1,100,120,000
Pre-tax net loss since the acquisition date																					103,540,000	$ 73,218,000	120,822,000
Constellation
Equity in earnings from real estate and other affiliates																							300,000
Ownership interest (as a percent)							50.00%
Portion of refinanced mortgage proceeds used to acquire partner's interest							$ 8,000,000.0
Liabilities acquired percentage							50.00%
Purchase price of acquisition							$ 16,000,000.0
Gain recognized from acquisition							17,800,000
Assets acquired and consolidated into financial statements							43,561,000
Constellation | Construction Loan Payable
Construction loan							$ 15,800,000
Constellation | Constellation Note Payable
Interest rate (as a percent)							4.07%
Aggregate principal amount of debt issued							$ 24,200,000
Las Vegas 51s
Adjustment to allocate from identified finite-lived intangibles								$ 7,900,000
Landmark Mall
Area of real estate property | a										11.4
Purchase price of acquisition										$ 22,200,000
Bridges At Mint Hill L L C
Economic/legal ownership		90.50%
Equity in earnings from real estate and other affiliates		$ 9,500,000																			8,800,000
Assets divested from deconsolidation		$ 22,000,000.0
Pre-tax net loss since the acquisition date																					$ 3,800,000
Las Vegas 51s
Economic/legal ownership								50.00%
Equity in earnings from real estate and other affiliates																							200,000
Portion of refinanced mortgage proceeds used to acquire partner's interest								$ 16,400,000
Gain recognized from acquisition								5,400,000
Contingent liability recorded per the terms of the purchase agreement								400,000
Adjustment to allocate from identified finite-lived intangibles								$ 36,000,000.0
Acquired intangible assets weighted average amortization period								11 years
Assets acquired and consolidated into financial statements								$ 24,900,000
Liabilities assumed and consolidated into financial statements								$ 3,200,000
Revenues																							$ 1,300,000
Revenues since the acquisition date																				$ 6,800,000
Pre-tax net loss since the acquisition date																				$ 600,000
Five non-core assets | Disposal by Sale
Proceeds from sale of real estate																			$ 52,600,000
Number of assets sold | item																			5
(Loss) gain on disposal of operating assets																			$ 23,100,000
Corporate gains on sale of properties																			19,200,000
Gain (Loss) on disposition of business																			$ 3,900,000
The Outlet Collection, Elk Grove
Area of land | a									100
Area of land under development | a									64
The Outlet Collection, Elk Grove | Disposal by Sale
Proceeds from sale of real estate									$ 36,000,000.0
Corporate gains on sale of properties									$ 32,200,000
Area of land sold | a									36
The Woodlands Towers at The Waterway
Square footage of building | ft²	807,586										595,854										595,854
The Woodlands Warehouse
Square footage of building | ft²	125,801
Waterway Land
Area of land | a	9.3
Payments to acquire real estate	$ 565,000,000.0
Century Park
Asset acquisition, number of buildings acquired | building	17
Square footage of building | ft²	1,300,000
Area of land | a	63
The Woodlands Towers At The Waterway And The Woodlands Warehouse
Duration of lease	13 years
West Windsor, New Jersey
Assets divested from deconsolidation			$ 27,500,000
Proceeds from sale of real estate			$ 40,000,000.0
Gain (loss) on sale or disposal of real estate and other assets, net																					$ 12,000,000.0
Area of land sold | a			658
Cottonwood Mall
Square footage of building | ft²				196,975
Assets divested from deconsolidation				$ 21,500,000
Proceeds from sale of real estate				46,000,000.0
Gain (loss) on sale or disposal of real estate and other assets, net																					$ 24,100,000
Proceeds from sales of properties				10,000,000.0
Nontrade receivables				$ 36,000,000.0
Interest rate (as a percent)				5.00%
Land Parcel, Holladay, Utah
Area of land sold | a				54
250 Water Street
Area of land purchased | a						1
Purchase price of land acquired						$ 180,000,000.0
Payments to acquire land						$ 53,100,000
Notes Payable, Other Payables | 250 Water Street
Interest rate (as a percent)						6.00%
Short-term debt						$ 129,700,000
Interest free term						6 months
Number of extension options | extention_option						3
Extension option, term						6 months
The Woodlands Towers at The Waterway
Asset acquisition, number of buildings acquired | building	2
Square footage of building | ft²	1,403,440
Leasing commission	$ 18,599,000