STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION EXPENSE - Employee Stock Purchase Plan Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 purchase_period participant	Dec. 31, 2013	Dec. 31, 2012
Stockholders Equity And Share Based Compensation Expense [Abstract]
Shares reserve for issuance under Employee stock purchase plan (in shares)	7,000,000
ESPP purchase consideration as percentage of market value (in hundredths)	85.00%
ESPP offering period	12 months
ESPP number of purchase periods per offering period	2
Number of months in each purchase period	6 months
Look-back period for ESPP	12 months
Percentage of gross compensation through payroll deductions employees can invest (in hundredths)	15.00%
Number of shares of common stock employee permitted to purchase (in shares)	750
Number of participants in ESPP	451
Number of shares issued ESPP (in shares)	300,000
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased	$ 6.49
Allocated Share-based Compensation Expense	$ 1.8	$ 0.7	$ 0.6