Statements of Financial Position Consolidated Balance Sheet - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Cash and Cash Equivalents, at Carrying Value	$ 36,735	$ 43,114
Marketable Securities, Current	119,444	113,871
Accounts Receivable, Net, Current	61,185	51,603
Inventory, Net	69,266	63,344
Deferred Tax Assets, Net, Current	8,986	8,986
Prepaid Expense and Other Assets	7,512	9,403
Assets, Current	303,128	290,321
Property, Plant and Equipment, Net	12,787	12,938
Goodwill	22,495	22,495
Intangible Assets, Net (Excluding Goodwill)	8,013	9,042
Other Assets, Noncurrent	31,449	31,841
Assets	377,872	366,637
Liabilities, Current [Abstract]
Accounts Payable and Accrued Liabilities	25,451	17,747
Other Liabilities, Current	17,884	17,188
Liabilities, Current	43,335	34,935
Convertible senior notes	56,399	54,773
Other Liabilities, Noncurrent	9,937	9,601
Liabilities	$ 109,671	$ 99,309
Commitments and Contingencies
Stockholders' Equity Attributable to Parent [Abstract]
Common Stock, Value, Issued	$ 32	$ 32
Additional Paid in Capital, Common Stock	402,110	409,562
Accumulated Other Comprehensive Income (Loss), Net of Tax	(2,202)	(2,652)
Retained Earnings (Accumulated Deficit)	(131,739)	(139,614)
Stockholders' Equity Attributable to Parent	268,201	267,328
Liabilities and Equity	$ 377,872	$ 366,637