STOCKHOLDERS' EQUITY (Details) (USD $)	1 Months Ended
	Jun. 30, 2012	Sep. 30, 2012	Dec. 31, 2011
STOCKHOLDERS' EQUITY
Number of shares of common stock in an underwritten public offering pursuant to existing shelf registration statement	5,980,000
Proceeds from sale	$ 342,500,000
Accumulated Other Comprehensive Income
Foreign currency translation		24,246,000	21,066,000
Unrealized gain on marketable debt securities		883,000	2,103,000
Other		(1,503,000)	(1,107,000)
Total accumulated other comprehensive income		$ 23,626,000	$ 22,062,000