CONVERTIBLE NOTES (Schedule of Net Carrying Amount) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Net carrying amount | $ 922,974 | $ 834,440 | |
| Amortization of debt discount and issuance costs | 5,298 | 29,954 | $ 20,938 |
| 2025 Convertible notes [Member] | |||
| Principal outstanding | 575,000 | 575,000 | |
| Unamortized debt discount | 0 | (109,655) | |
| Unamortized debt issuance costs | (11,565) | (11,766) | |
| Net carrying amount | 563,435 | 453,579 | |
| Amortization of debt discount and issuance costs | 3,114 | 7,629 | |
| 2023 Convertible note [Member] | |||
| Principal outstanding | 442,750 | 442,750 | |
| Unamortized debt discount | 0 | (57,435) | |
| Unamortized debt issuance costs | (3,128) | (4,275) | |
| Converted to shares | (80,083) | (179) | |
| Net carrying amount | 359,539 | 380,861 | |
| Amortization of debt discount and issuance costs | $ 2,184 | $ 22,325 | $ 20,938 |