LONG-TERM DEBT (Schedule of Debt Interest Expense) (Details) - 2.5% Convertible Senior Notes Due 2023 [Member] - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended |
|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2018 |
|
| Debt Instrument [Line Items] | ||
| Contractual interest coupon | $ 3,361 | $ 7,257 |
| Amortization of debt discount | 2,996 | 5,951 |
| Amortization of debt issuance costs | 534 | 1,068 |
| Total interest cost recognized on the notes | $ 6,891 | $ 14,276 |
| X | ||||||||||
- Definition Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of amortization expense attributable to debt issuance costs. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| 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 Amount of the cost of borrowed funds accounted for as interest expense for debt. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|