Statements of Financial Position Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Cash and Cash Equivalents, at Carrying Value	$ 85,053	$ 104,253
Marketable Securities, Current	81,320	64,963
Accounts Receivable, Net, Current	52,683	57,113
Inventory, Net	70,275	63,422
Prepaid Expense and Other Assets	5,650	4,301
Assets, Current	294,981	294,052
Property, Plant and Equipment, Net	13,378	11,909
Goodwill	11,252	11,371
Intangible Assets, Net (Excluding Goodwill)	11,671	12,358
Other Assets, Noncurrent	36,465	36,694
Assets	367,747	366,384
Accounts Payable and Accrued Liabilities	17,857	15,696
Other Liabilities, Current	18,190	21,352
Liabilities, Current	36,047	37,048
Convertible senior notes	49,677	49,010
Other Liabilities, Noncurrent	10,018	9,837
Liabilities	95,742	95,895
Commitments and Contingencies
Common Stock, Value, Issued	32	32
Additional Paid in Capital, Common Stock	411,532	409,974
Accumulated Other Comprehensive Income (Loss), Net of Tax	(1,520)	(1,085)
Retained Earnings (Accumulated Deficit)	(138,039)	(138,432)
Stockholders' Equity Attributable to Parent	272,005	270,489
Liabilities and Equity	$ 367,747	$ 366,384