UNCONSOLIDATED AFFILIATES AND COST METHOD INVESTMENT - Joint Ventures (Details)	1 Months Ended							3 Months Ended					7 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) yr	Apr. 30, 2018 USD ($)	Nov. 30, 2017 USD ($)	Aug. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) office_building	Mar. 31, 2016 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Sep. 30, 2016 USD ($) subsidiary	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) yr	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 29, 2018 USD ($)	Jul. 31, 2016 USD ($)
Schedule of Equity Method Investments [Line Items]
Loss on impairment													$ 71,285,000		$ 174,529,000	$ 71,401,000	$ 116,822,000
Gross sales price															65,000,000	189,750,000	194,710,000
Net sales price															53,402,000	112,076,000	189,531,000
Gain (loss) on sales of real estate assets															19,001,000	93,792,000	29,567,000
Mortgage and other indebtedness, variable-rate debt	$ 955,751,000														955,751,000	1,090,810,000
Gain (loss) on extinguishment of debt																30,927,000
Mortgage debt assumed by buyer of real estate assets															0	0	38,150,000
Gain (loss) on investments																(6,197,000)	7,534,000
Mortgages
Schedule of Equity Method Investments [Line Items]
Mortgage note payables assumed																			$ 38,150,000
Non-Recourse Loans on Operating Properties
Schedule of Equity Method Investments [Line Items]
Mortgage and other indebtedness, variable-rate debt	0														0	10,836,000
CBL & Associates Properties, Inc.
Schedule of Equity Method Investments [Line Items]
Loss on impairment															174,529,000	71,401,000	116,822,000
Gain (loss) on sales of real estate assets															19,001,000	93,792,000	29,567,000
Gain (loss) on extinguishment of debt															0	30,927,000	0
Gain (loss) on investments															$ 0	$ (6,197,000)	7,534,000
G&I VIII CBL Triangle LLC
Schedule of Equity Method Investments [Line Items]
Loss on impairment		$ 89,826,000												$ 1,022,000
Fair value of real estate joint ventures		33,600,000												33,600,000				$ 123,453,000
Net real estate investments		$ 0												0
Renaissance Center
Schedule of Equity Method Investments [Line Items]
Gross sales price											$ 129,200,000
River Ridge Mall JV, LLC
Schedule of Equity Method Investments [Line Items]
Loss on impairment						$ 84,000						$ 9,510,000					9,594,000
Gross sales price							$ 33,500,000
Net sales price							32,905,000
Reserve for future capital expenditures																	$ 2,100,000
River Ridge Mall JV, LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Gain (loss) on sales of real estate assets									$ (5,843,000)
Renaissance Center - Phase I | Mortgages
Schedule of Equity Method Investments [Line Items]
Mortgage debt assumed by buyer of real estate assets											16,000,000
Defeasance of debt in disposition											31,484,000
Corporate Joint Venture | River Ridge Mall JV, LLC
Schedule of Equity Method Investments [Line Items]
Cash contributed by third party												33,500,000
Quoted market value							$ 7,000,000					7,000,000
Repayment of long term line of credit												$ 32,819,000
Continental 425 Fund LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Capital contribution, land	6,000,000
Cash contributed	$ 7,000
Membership units owned (as a percent)	43.50%
Self Storage at Mid Rivers, LLC
Schedule of Equity Method Investments [Line Items]
Realized investment gains (losses)			$ 387,000
Self Storage at Mid Rivers, LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)			50.00%
Self Storage at Mid Rivers, LLC | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)			50.00%
River Ridge Mall JV, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)						25.00%		25.00%					25.00%				25.00%
Proceeds from sale of joint venture														9,000,000
Loss on sale of investment					$ 354,000									$ 5,843,000
River Ridge Mall JV, LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)							25.00%					25.00%
River Ridge Mall JV, LLC | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)							75.00%					75.00%
Shoppes at Eagle Point, LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)								50.00%					50.00%
Shoppes at Eagle Point, LLC | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)								50.00%					50.00%
Cash contributed by third party								$ 1,031,000
EastGate Storage, LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Capital contribution, land				$ 1,134,000
Ownership interest in joint venture (as a percent)				50.00%
EastGate Storage, LLC | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)				50.00%
JG Gulf Coast Town Center LLC
Schedule of Equity Method Investments [Line Items]
Gain (loss) on investments											$ 29,267,000
JG Gulf Coast Town Center LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)											50.00%
JG Gulf Coast Town Center LLC | Non-Recourse Loans on Operating Properties
Schedule of Equity Method Investments [Line Items]
Mortgage and other indebtedness, variable-rate debt											$ 190,800,000
JG Gulf Coast Town Center LLC | CBL & Associates Properties, Inc. | Non-Recourse Loans on Operating Properties
Schedule of Equity Method Investments [Line Items]
Mortgage and other indebtedness, variable-rate debt											95,400,000
JG Gulf Coast Town Center LLC | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Gain (loss) on extinguishment of debt											63,294,000
Gulf Coast Town Center - Phase III
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)																50.00%
Gulf Coast Town Center - Phase III | Parent Company
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)																50.00%
CBL-TRS Joint Venture, LLC | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Number of office buildings sold (office building) | office_building						4
Gross sales price						$ 26,000,000
Net sales price						25,406,000				$ 14,962,000
Gain (loss) on sales of real estate assets						51,000
CBL-TRS Joint Venture, LLC | Corporate Joint Venture | Other Ownership Interest
Schedule of Equity Method Investments [Line Items]
Net sales price						12,703,000
Gain (loss) on sales of real estate assets						25,000
Triangle Town Member LLC
Schedule of Equity Method Investments [Line Items]
Gain (loss) on sales of real estate assets						$ 2,820,000
Triangle Town Member LLC | Parent Company
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)						10.00%	50.00%					50.00%					10.00%
Gain (loss) on sales of real estate assets						$ 282,000
Triangle Town Member LLC | Mortgages | Parent Company
Schedule of Equity Method Investments [Line Items]
Mortgage note payables assumed							$ 17,109,000					$ 17,109,000
Triangle Town Member LLC | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)						90.00%	50.00%					50.00%					90.00%
Gross sales price						$ 30,250,000						$ 174,000,000
Net sales price						29,802,000
Gain (loss) on sales of real estate assets						2,538,000						80,979,000
Mortgage and other indebtedness, variable-rate debt						$ 29,342,000											$ 29,342,000
Equity contribution												3,060,000
Triangle Town Member LLC | Corporate Joint Venture | Mortgages
Schedule of Equity Method Investments [Line Items]
Mortgage note payables assumed							$ 171,092,000					171,092,000
Triangle Town Member LLC | Corporate Joint Venture | Mortgages | Other Ownership Interest
Schedule of Equity Method Investments [Line Items]
Mortgage note payables assumed							$ 85,546,000					$ 85,546,000
High Pointe Commons, LP and High Pointe Commons II-HAP, LP
Schedule of Equity Method Investments [Line Items]
Number of subsidiaries owned by the company (subsidiary) | subsidiary										2
High Pointe Commons | Parent Company
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)										50.00%
High Pointe Commons | Mortgages
Schedule of Equity Method Investments [Line Items]
Extinguishment of debt										$ 17,388,000
High Pointe Commons | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest in joint venture (as a percent)										50.00%
Gross sales price										$ 33,800,000
Gain (loss) on sales of real estate assets										16,649,000
Gain (loss) on extinguishment of debt										(393,000)
High Pointe Commons | Corporate Joint Venture | Other Ownership Interest
Schedule of Equity Method Investments [Line Items]
Net sales price										7,481,000
Gain (loss) on sales of real estate assets										8,324,000
Gain (loss) on extinguishment of debt										$ (197,000)
Renaissance Center | Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Net sales price											80,324,000
Gain (loss) on sales of real estate assets											59,977,000
Renaissance Center | Corporate Joint Venture | Other Ownership Interest
Schedule of Equity Method Investments [Line Items]
Net sales price											40,162,000
Gain (loss) on sales of real estate assets											$ 29,989,000
Expected Term | G&I VIII CBL Triangle LLC
Schedule of Equity Method Investments [Line Items]
Measurement input | yr		10												10
Cap Rate (as a percent) | G&I VIII CBL Triangle LLC
Schedule of Equity Method Investments [Line Items]
Measurement input		0.15												0.15
Discount Rate (as a percent) | G&I VIII CBL Triangle LLC
Schedule of Equity Method Investments [Line Items]
Measurement input		0.15												0.15