SEGMENT AND GEOGRAPHIC INFORMATION, Revenue by Geographic Region (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 295,623	$ 267,474	$ 310,746
Number of major customers	0
Minimum percentage of revenue major customer accounted for (in hundredths)	10.00%
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	171,176	142,508	178,029
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	71,526	76,286	80,914
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	21,039	19,989	22,248
Other countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 31,882	$ 28,691	$ 29,555