EARNINGS (LOSS) PER SHARE (Computation of basic and diluted earnings (loss) per share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Basic
Net income (loss) - basic (in dollars per share)	$ (0.35)	$ (0.15)	$ (0.18)	$ (0.25)	$ (0.01)	$ (0.07)	$ 0.01	$ (0.10)	$ (0.94)		$ (0.17)		$ 0.35
Diluted
Net income (loss) - diluted (in dollars per share)	$ (0.35)	$ (0.15)	$ (0.18)	$ (0.25)	$ (0.01)	$ (0.07)	$ 0.01	$ (0.10)	$ (0.94)		$ (0.17)		$ 0.34
EPS numerator - basic and diluted:
Net income (loss)	$ (11,296)	$ (5,047)	$ (5,811)	$ (8,241)	$ (343)	$ (2,165)	$ 394	$ (3,221)	$ (30,395)		$ (5,335)		$ 10,909
EPS denominator (in thousands):
Weighted-average common stock outstanding - basic (in shares)	32,600	32,600	32,717	32,344	32,169	32,156	32,122	31,765	32,493		32,060		31,566
Common stock equivalents: stock options and other stock-based awards (a) (in shares)									0	[1]	0	[1]	423	[1]
Weighted-average number of common stock outstanding - diluted (in shares)	32,600	32,600	32,717	32,344	32,169	32,156	32,486	31,765	32,493		32,060		31,989

[1] For the periods in which net losses are presented, the diluted weighted average number of shares of common stock outstanding did not differ from the basic weighted average number of shares of common stock outstanding because the effects of any potential common stock equivalents (see Note 4 for further details on outstanding stock options, unvested restricted stock units and unvested restricted stock) were anti-dilutive and therefore not included in the calculation of the denominator of dilutive earnings per share.