SEGMENT INFORMATION - Reconciliation of Consolidated Net Income (Loss) to Consolidated NOI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting [Abstract]
Net income	$ 307,326	$ 34,529	$ 135,472
Plus:
Interest expense	73,911	81,512	78,199
Interest expense - amortization of deferred financing costs	2,904	2,768	2,498
Depreciation and amortization	188,283	210,005	176,000
General and administrative expenses	30,288	32,156	27,802
Equity in loss of Real Estate Ventures	18,584	9,922	15,231
Provision for impairment	0	0	71,707
Loss on early extinguishment of debt	0	0	105
Less:
Interest income	1,939	2,318	4,703
Income tax (provision) benefit	224	(12)	(423)
Net gain on disposition of real estate	289,461	356	2,932
Net gain on sale of undepreciated real estate	201	2,020	3,040
Net gain on real estate venture transactions	75	11,639	142,233
Gain on promoted interest in unconsolidated real estate venture	0	0	28,283
Consolidated net operating income	$ 329,396	$ 354,571	$ 326,246