SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of basic and diluted net loss per share - (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounting Policies [Abstract]
Net loss and net loss available to common stockholders	$ 21	$ (2,450)	$ (1,997)	$ 107	$ 4,198	$ (1,788)	$ (2,612)	$ (1,500)	$ (4,318)	$ (1,702)	$ (3,622)
Weighted average shares outstanding, basic and diluted									50,761	50,422	50,467
Net loss per share, basic and diluted	$ 0.00	$ (0.05)	$ (0.04)	$ 0.00	$ 0.08	$ (0.04)	$ (0.05)	$ (0.03)	$ (0.09)	$ (0.03)	$ (0.07)
Anti-dilutive securities excluded from diluted net loss per share calculation for stock-based compensation plans									5,909	5,816	5,750