Unaudited Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Revenue	$ 102,575	$ 78,243
Cost of revenue	58,894	45,613
Gross margin	43,681	32,630
Expenses:
Selling, general and administrative	21,572	18,017
Depreciation and amortization	2,285	1,190
Research and development	1,026	875
Total expenses	24,883	20,082
Income from operations	18,798	12,548
Other income (expense):
Interest expense	(454)	(434)
Other income (expense), net	54	(112)
Total other income (expense)	(400)	(546)
Income before income taxes	18,398	12,002
Income tax expense	(6,380)	(4,237)
Net income	$ 12,018	$ 7,765
Earnings per common share:
Basic earnings per common share	$ 0.22	$ 0.16
Diluted earnings per common share	$ 0.22	$ 0.15
Weighted average common shares:
Weighted average common shares used in computing basic earnings per common share	53,948	48,582
Weighted average common shares used in computing diluted earnings per common share	55,398	51,222