|
FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS (Details) (USD $)
|
3 Months Ended | 12 Months Ended |
|---|---|---|
|
Mar. 31, 2015
|
Dec. 31, 2014
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Other-than-temporary impairment charges | $ 0 | $ 100,000 |
| 4.00% Convertible Senior Notes | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Debt Instrument, Interest Rate, Stated Percentage | 4.00% | |
| Convertible debt fair value | $ 241,200,000 |