CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) (USD $)	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2011	$ 62,651,000	$ 923,000	$ 248,480,000	$ (186,465,000)	$ (287,000)
Balance (in shares) at Dec. 31, 2011		92,261,057
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(18,791,000)	0	0	(18,791,000)	0
Change in unrealized gain (loss) on fair value of investments	(25,000)	0	0	0	(25,000)
Foreign currency translation adjustment	343,000	0	0	0	343,000
Stock-based compensation	2,091,000	0	2,091,000	0	0
Stock options exercised	431,000	4,000	427,000	0	0
Stock options exercised (in shares)		390,957
Restricted stock issued, net of cancellations	0	0	0	0	0
Restricted stock issued, net of cancellations (in shares)		81,434
Balance at Dec. 31, 2012	46,700,000	927,000	250,998,000	(205,256,000)	31,000
Balance (in shares) at Dec. 31, 2012		92,733,448
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	38,647,000	0	0		0
Change in unrealized gain (loss) on fair value of investments	(79,000)	0	0	0	(79,000)
Foreign currency translation adjustment	(559,000)	0	0	0	(559,000)
Stock-based compensation	2,114,000	0	2,114,000	0	0
Stock options exercised	83,000	2,000	81,000	0	0
Stock options exercised (in shares)		129,686
Restricted stock issued, net of cancellations	0	0	0	0	0
Restricted stock issued, net of cancellations (in shares)		42,915
Balance at Dec. 31, 2013	86,906,000	929,000	253,193,000	(166,609,000)	(607,000)
Balance (in shares) at Dec. 31, 2013	92,906,049	92,906,049
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	63,269,000	0	0		0
Change in unrealized gain (loss) on fair value of investments	0
Foreign currency translation adjustment	607,000	0	0	0	607,000
Stock-based compensation	2,703,000	0	2,703,000	0	0
Stock options exercised	255,000	3,000	252,000	0	0
Stock options exercised (in shares)		238,157
Restricted stock issued, net of cancellations	0	15,000	(15,000)	0	0
Restricted stock issued, net of cancellations (in shares)		1,542,472
Balance at Dec. 31, 2014	$ 207,495,000	$ 1,062,000	$ 309,773,000	$ (103,340,000)	$ 0
Balance (in shares) at Dec. 31, 2014	106,186,678	106,186,678