STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION EXPENSE - Stock Options Plan Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Options, Outstanding [Roll Forward]
Outstanding at beginning of the period (in shares)	6,101
Grants (in shares)	988
Exercises (in shares)	(424)
Forfeitures or expirations (in shares)	(1,523)
Outstanding at end of the period (in shares)	5,142
Exercisable (in shares)	2,979
Vested and expected to vest (in shares)	4,808
Weighted Average Exercise Price Per Share [Roll Forward]
Outstanding at beginning of the period (in dollars per share)	$ 7.75
Grants (in dollars per share)	$ 4.43
Exercises (in dollars per share)	$ 4.03
Forfeitures or expirations (in dollars per share)	$ 10.02
Outstanding at end of the period (in dollars per share)	$ 6.75
Exercisable (in dollars per share)	$ 8.36
Vested and expected to vest (in dollars per share)	$ 6.91
Weighted-Average Remaining Contractual Terms [Abstract]
Outstanding at end of the period	3 years 10 months 13 days
Exercisable	2 years 8 months 4 days
Vested and expected to vest	3 years 8 months 19 days
Aggregate Intrinsic Value [Abstract]
Outstanding at end of the period	$ 15,475
Exercisable	6,761
Vested and expected to vest	$ 14,121