FAIR VALUE MEASUREMENTS (Fair Value of Debt) (Details) - Level 2 [Member] - USD ($) $ in Thousands |
Jun. 30, 2019 |
Dec. 31, 2018 |
|---|---|---|
| 4.875% Senior Notes Due 2024 [Member] | ||
| Debt Fair Value [Line Items] | ||
| Estimated fair values of senior notes | $ 592,204 | $ 552,368 |
| 5.625% Senior Notes Due 2026 [Member] | ||
| Debt Fair Value [Line Items] | ||
| Estimated fair values of senior notes | 315,129 | 302,097 |
| 5.375% Senior Notes due 2022 [Member] | ||
| Debt Fair Value [Line Items] | ||
| Estimated fair values of senior notes | 254,243 | 251,390 |
| 2.5% Convertible Senior Notes Due 2023 [Member] | ||
| Debt Fair Value [Line Items] | ||
| Estimated fair values of convertible senior notes | 652,141 | 561,699 |
| 2.5% Convertible Senior Notes Due 2019 [Member] | ||
| Debt Fair Value [Line Items] | ||
| Estimated fair values of convertible senior notes | $ 0 | $ 40,710 |
| X | ||||||||||
- Definition Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock. No definition available.
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|