INCOME TAXES (Summary of Tax Effects and Temporary Differences Included in Net Deferred Tax Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Operating and Strategic Developments properties, primarily differences in basis of assets and liabilities	$ 51,580	$ 65,590
Operating loss and tax carryforwards	161,701	132,277
Total deferred tax assets	213,281	197,867
Valuation allowance	(38,065)	(29,723)
Total net deferred tax assets	175,216	168,144
Deferred tax liabilities:
Property associated with MPCs, primarily differences in the tax basis of land assets and treatment of interest and other costs	(163,836)	(163,024)
Operating and Strategic Developments properties, primarily differences in basis of assets and liabilities	(100,564)	(67,125)
Deferred income	(98,455)	(118,743)
Total deferred tax liabilities	(362,855)	(348,892)
Total net deferred tax liabilities	$ (187,639)	$ (180,748)