Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012
Cash Flows from Operating Activities
Net (loss) income	$ (20,178)	$ 39,983
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	12,080	12,181
Deferred income taxes	(5,196)	278
Non-cash equity-based compensation	9,054	10,629
Gain on disposal of segment		(4,112)
Excess tax benefits from stock option exercises	(485)	(2,211)
Non-cash items from discontinued operations		(904)
Other, net	20	10
Changes in operating assets and liabilities:
Accounts receivable	25,095	34,486
Inventories	2,165	40,271
Prepaid expenses and other current assets	(4,801)	(219)
Accounts payable	2,307	(2,811)
Accrued expenses, deferred revenue and other current liabilities	(15,235)	(24,897)
Income taxes payable	(821)	(224)
Other, net	605	5,307
Discontinued operations		(1,932)
Net cash provided by operating activities	4,610	105,835
Cash Flows from Investing Activities
Capital expenditures	(7,976)	(22,706)
Proceeds from liquidations of short-term investments	422,903	176,303
Payments for purchases of short-term investments	(553,217)	(89,848)
Payment for purchase of cost method investment	(1,594)	(10,341)
Proceeds from sale of assets from discontinued segment		3,758
Other	25	58
Net cash (used in) provided by investing activities	(139,859)	57,224
Cash Flows from Financing Activities
Proceeds from stock option exercises	313	5,370
Restricted stock tax withholdings	(2,358)	(1,418)
Excess tax benefits from stock option exercises	485	2,211
Repayments of long-term debt	(199)	(184)
Net cash (used in) provided by financing activities	(1,759)	5,979
Effect of exchange rate changes on cash and cash equivalents	117	88
Net (decrease) increase in cash and cash equivalents	(136,891)	169,126
Cash and cash equivalents at beginning of period	384,557	217,922
Cash and cash equivalents at end of period	247,666	387,048
Non-cash investing and financing activities
Transfers from property, plant and equipment to inventory	2,224	1,242
Transfers from inventory to property, plant and equipment	$ 1,144

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.