ACCRUED LIABILITIES (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accrued liabilities consist of:
Bonuses and accrued vacation	$ 6,928	$ 4,881
Tax contingencies and accruals for unrecognized income tax benefits	2,588	6,498
Auditing and consulting services	2,531	789
Accrued equity-based incentive awards	3,876	4,487
Other accrued liabilities	7,522	4,738
Total accrued liabilities	$ 23,445	$ 21,393