Statement of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Net Income (Loss) Attributable to Parent	$ 36,952	$ 17,956	$ (4,640)
Depreciation	3,677	3,951	4,686
Amortization of Financing Costs and Discounts	2,154	3,766	3,385
Amortization	2,320	2,145	2,427
Foreign Currency Transaction Loss (Gain), before tax	592	293	65
Gain (Loss) on Disposition of Property Plant Equipment	(946)	0	0
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Asset	170	(630)	120
Share-based Compensation	4,775	7,603	6,242
Provision for doubtful accounts and inventory valuation	2,971	3,826	4,064
Increase (Decrease) in Deferred Income Taxes	5,011	3,980	(3,937)
Increase (Decrease) in Accounts Receivable	(9,279)	(4,336)	1,147
Increase (Decrease) in Income Taxes Receivable	(3,813)	2,610	1,196
Increase (Decrease) in Inventories	4,003	(12,529)	(9,393)
Increase (Decrease) in Prepaid Expense and Other Assets	2,038	953	(4,690)
Increase (Decrease) in Accounts Payable	1,169	2,254	3,758
Increase (Decrease) in Deferred Revenue	896	(1,535)	363
Increase (Decrease) in Other Operating Liabilities	(6,057)	3,486	(503)
Net Cash Provided by (Used in) Operating Activities	46,633	33,793	4,290
Net Cash Provided by (Used in) Investing Activities [Abstract]
Payments to Acquire Marketable Securities	(146,865)	(237,127)	(243,656)
Proceeds from Sale and Maturity of Marketable Securities	175,460	234,105	217,212
Payments to Acquire Property, Plant, and Equipment	(3,291)	(3,359)	(2,084)
Payments to Acquire Intangible Assets	(2,000)	(2,696)	0
Payments to Acquire Businesses, Net of Cash Acquired	1,165	0	0
Net Cash Provided by (Used in) Investing Activities	24,469	(9,077)	(28,528)
Debt Instrument, Redemption	(60,000)	0	0
Payments for Repurchase of Warrants	9,500
Proceeds from Warrant Exercises		0	0
Net Cash Provided by (Used in) Financing Activities [Abstract]
Payments for (Proceeds from) Derivative Instrument, Financing Activities	(8,044)	(20,668)	(12,845)
Payments Related to Tax Withholding for Share-based Compensation	(1,587)	(1,916)	0
Proceeds from (Payments for) Other Financing Activities	(622)	(731)	(264)
Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Including Stock Options	850	330	362
Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Financing Activities	792	16	63
Net Cash Provided by (Used in) Financing Activities	(78,111)	(22,969)	(12,684)
Effect of Exchange Rate on Cash and Cash Equivalents	314	(307)	(754)
Cash and Cash Equivalents, Period Increase (Decrease)	(6,695)	1,440	(37,676)
Cash and Cash Equivalents, at Carrying Value	37,859	44,554	43,114
Supplemental Cash Flow Information [Abstract]
Income Taxes Paid	10,980	2,013	1,067
Interest Paid	2,250	2,250	2,250
Litigation settlement received	(14,643)
Payments for Legal Settlements		0	10,613
Noncash or Part Noncash Acquisition, Intangible Assets Acquired	$ 0	$ 3,000	$ 0