BASIS OF PRESENTATION AND OTHER INFORMATION (Impact of Adoption of Accounting Standard) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	$ (3,317,397)	$ (3,327,737)
Total equity	(145,617)	(188,454)	$ (394,114)	$ (133,752)
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		(35,464)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	(3,317,397)	(3,327,737)	(2,984,026)	(2,676,833)
Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		60,522
Additional Paid-in Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	$ 2,888,551	2,897,695	$ 2,431,387	$ 2,386,790
Additional Paid-in Capital | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		(95,986)
Accounting Standards Update 2020-06
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Convertible Debt, Current		14,700
Convertible Debt, Noncurrent		$ 20,800