FAIR VALUE MEASUREMENTS (Fair Value of Senior Notes) (Details) - Fair value, inputs, Level 2 [Member] - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value Measurements
Carrying amount of senior notes	$ 3,825,177	$ 4,123,217
Estimated fair value of senior notes	$ 4,173,269	$ 4,647,595

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Name:	us-gaap_DebtInstrumentFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant