Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash Flows from Operating Activities
Net (loss) income	$ (10,071)	$ 16,412
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	3,927	3,715
Deferred income taxes	(6,215)	674
Non-cash equity-based compensation	2,579	3,130
Provision for bad debt	16
Excess tax benefits from stock option exercises	(31)	(91)
Other, net		14
Changes in operating assets and liabilities:
Accounts receivable	20,004	5,079
Inventories	(8,395)	10,599
Accounts payable	6,458	(2,179)
Accrued expenses, deferred revenue and other current liabilities	1,764	(7,169)
Income taxes payable	(1,555)	(1,556)
Other, net	2,005	13,007
Net cash provided by operating activities	10,486	41,635
Cash Flows from Investing Activities
Capital expenditures	(1,619)	(8,455)
Proceeds from sales of short-term investments	101,236	43,569
Payments for purchases of short-term investments	(271,713)	(18,503)
Net cash (used in) provided by investing activities	(172,096)	16,611
Cash Flows from Financing Activities
Proceeds from stock option exercises	280	537
Restricted stock tax withholdings	(132)	(95)
Excess tax benefits from stock option exercises	31	91
Repayments of long-term debt	(65)	(60)
Net cash provided by financing activities	114	473
Effect of exchange rate changes on cash and cash equivalents	60	(1,309)
Net (decrease) increase in cash and cash equivalents	(161,436)	57,410
Cash and cash equivalents as of beginning of period	384,557	217,922
Cash and cash equivalents as of end of period	223,121	275,332
Non-cash investing and financing activities
Transfers from property, plant and equipment to inventory	$ 135