Statement of Financial Position - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets, Current [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 44,554	$ 43,114
Marketable Securities, Current	116,924	113,871
Accounts Receivable, Net, Current	55,492	51,603
Inventory, Net	71,490	63,344
Income Taxes Receivable	0	1,458
Prepaid Expense and Other Assets	8,137	7,945
Assets, Current	296,597	281,335
Property, Plant and Equipment, Net	12,346	12,938
Goodwill	22,495	22,495
Intangible Assets, Net (Excluding Goodwill)	12,593	9,042
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	34,973	39,334
Other Assets, Noncurrent	820	1,493
Assets	379,824	366,637
Liabilities, Current [Abstract]
Accounts Payable, Current	9,094	6,843
Accrued Liabilities, Current [Abstract]
Employee-related Liabilities, Current	10,142	8,831
Accrued Royalties	336	499
Product Warranty Accrual, Current	1,894	1,574
Convertible Debt, Current	58,107	0
Taxes Payable, Current	1,163	0
Deferred Revenue	6,441	7,045
Other Liabilities, Current	12,415	10,143
Liabilities, Current	99,592	34,935
Convertible Debt, Noncurrent	0	54,773
Other Liabilities, Noncurrent	9,554	9,601
Liabilities	109,146	99,309
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock issued and outstanding	0	0
Common Stock, Value, Issued	31	32
Additional Paid in Capital, Common Stock	394,928	409,562
Accumulated Other Comprehensive Income (Loss), Net of Tax	(2,623)	(2,652)
Retained Earnings (Accumulated Deficit)	(121,658)	(139,614)
Stockholders' Equity Attributable to Parent	270,678	267,328
Liabilities and Equity	$ 379,824	$ 366,637