Unaudited Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Revenue	$ 98,388	$ 78,628	$ 270,217	$ 236,126
Cost of revenue	60,886	44,785	162,491	135,807
Gross margin	37,502	33,843	107,726	100,319
Expenses:
Selling, general and administrative	19,542	17,171	58,640	47,860
Depreciation and amortization	2,038	1,170	5,231	3,166
Research and development	835	909	2,689	2,363
Total expenses	22,415	19,250	66,560	53,389
Income from operations	15,087	14,593	41,166	46,930
Other income (expense):
Loss on extinguishment of debt	0	0	0	(6,386)
Change in fair value of warrant liability	0	0	0	2,649
Interest expense	(530)	(1,830)	(1,495)	(6,245)
Other income (expense), net	59	(17)	117	(367)
Total other income (expense)	(471)	(1,847)	(1,378)	(10,349)
Income before income taxes	14,616	12,746	39,788	36,581
Income tax expense	(5,648)	(2,940)	(14,615)	(9,991)
Net income	$ 8,968	$ 9,806	$ 25,173	$ 26,590
Earnings per common share:
Basic earnings per common share	$ 0.17	$ 0.20	$ 0.50	$ 0.55
Diluted earnings per common share	$ 0.16	$ 0.19	$ 0.47	$ 0.52
Weighted average common shares:
Weighted average common shares used in computing basic earnings per common share	52,742	48,384	50,819	48,054
Weighted average common shares used in computing diluted earnings per common share	55,317	53,478	53,407	50,737