Statement of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues	$ 221,690	$ 181,218	$ 176,238
Cost of Revenue	102,284	85,730	85,506
Gross Profit	119,406	95,488	90,732
Operating Expenses [Abstract]
Research and Development Expense	41,233	40,576	39,994
Selling, General and Administrative Expense	43,235	53,799	41,542
Amortization of Intangible Assets	2,145	2,422	2,592
Operating Expenses	86,613	96,797	84,128
Operating Income (Loss)	32,793	(1,309)	6,604
Interest Income (Expense), Net	5,688	5,317	5,079
Other Nonoperating Expense (Income)	293	65	(8)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	26,812	(6,691)	1,533
Income Tax Expense (Benefit)	8,856	(2,051)	(1,925)
Net Income (Loss) Attributable to Parent	$ 17,956	$ (4,640)	$ 3,458
Earnings Per Share, Basic	$ 0.57	$ (0.14)	$ 0.11
Earnings Per Share, Diluted	$ 0.56	$ (0.14)	$ 0.10
Weighted Average Number of Shares Outstanding, Basic	31,408	33,124	32,783
Weighted Average Number of Shares Outstanding, Diluted	32,166	33,124	33,388