Statements of Cash Flows Statement - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Net Income (Loss) Attributable to Parent	$ 21,540	$ 7,875
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Amortization	1,190	1,030
Amortization of Financing Costs and Discounts	2,039	1,833
Depreciation	1,868	1,907
Foreign Currency Transaction Gain (Loss), before Tax	299	426
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Asset	117	(319)
Share-based Compensation	2,387	5,430
Provision for doubtful accounts and inventory valuation	2,278	2,521
Gain (Loss) Related to Litigation Settlement	(14,632)	0
Increase (Decrease) in Other Operating Assets and Liabilities, Net	(5,104)	(6,707)
Net Cash Provided by (Used in) Operating Activities	11,982	13,996
Net Cash Provided by (Used in) Investing Activities [Abstract]
Payments to Acquire Marketable Securities	(70,412)	(109,466)
Proceeds from Sale and Maturity of Marketable Securities	90,599	104,160
Payments to Acquire Property, Plant, and Equipment	(2,173)	(1,744)
Net Cash Provided by (Used in) Investing Activities	18,014	(7,050)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Payments for Repurchase of Common Stock	(8,044)	(11,197)
Payments Related to Tax Withholding for Share-based Compensation	(1,565)	(1,895)
Proceeds from (Payments for) Other Financing Activities	(94)	(141)
Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Including Stock Options	275	174
Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Financing Activities	252	36
Net Cash Provided by (Used in) Financing Activities	(9,176)	(13,023)
Effect of Exchange Rate on Cash and Cash Equivalents	1,065	(302)
Cash and Cash Equivalents, Period Increase (Decrease)	21,885	(6,379)
Cash and Cash Equivalents, at Carrying Value	66,439	36,735
Supplemental Cash Flow Information [Abstract]
Income Taxes Paid	2,541	139
Interest Paid	$ 1,125	$ 1,125