CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ (15,661)	$ (46,248)	$ 37,027
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Amortization of intangibles	6,502	20,520	27,329
Depreciation	13,241	16,459	16,641
Stock-based compensation	15,582	17,287	16,089
Amortization of discount on convertible debt	216	0	0
Gain on sale of discontinued operations, net of tax	0	0	(14,663)
Restructuring, asset impairment and (gain) loss on retirement of fixed assets	641	1,622	244
Loss on impairment of long-term investment	2,505	0	0
Deferred income taxes, net	(512)	32,163	(8,537)
Provision for doubtful accounts, returns and discounts	2,034	1,943	960
Provision for excess and obsolete inventories	1,585	2,569	3,475
Excess tax benefits from stock-based compensation	0	(15)	(141)
Other non-cash adjustments, net	0	1,108	2,098
Changes in assets and liabilities:
Accounts receivable	2,595	(1,035)	9,908
Inventories	(5,954)	1,610	13,290
Prepaid expenses and other assets	(8,206)	(3,332)	1,807
Accounts payable	4,683	56	(3,363)
Deferred revenues	(4,541)	11,162	(1,922)
Income taxes payable	(1,637)	(7,094)	(40,546)
Accrued and other liabilities	(6,722)	(1,406)	(5,937)
Net cash provided by operating activities	6,351	47,369	53,759
Cash flows from investing activities:
Purchases of investments	(25,261)	(26,599)	(78,764)
Proceeds from maturities of investments	30,379	60,811	63,034
Proceeds from sales of investments	0	13,045	37,890
Purchases of property and equipment	(14,356)	(10,065)	(14,581)
Proceeds from sale of discontinued operations, net of selling costs	0	0	43,515
Purchases of long-term investments	(85)	(9,393)	0
Restricted cash	(1,091)	0	0
Net cash provided by (used in) investing activities	(10,414)	27,799	51,094
Cash flows from financing activities:
Proceeds from convertible debt	128,250	0	0
Payment of convertible debt issuance cost	(3,527)	0	0
Proceeds from common stock issued to employees	9,222	4,742	8,521
Payment of tax withholding obligations related to net share settlements of restricted stock units	(3,549)	(3,636)	(3,335)
Payments for repurchases of common stock	(72,863)	(93,128)	(116,529)
Excess tax benefits from stock-based compensation	0	15	141
Net cash provided by (used in) financing activities	57,533	(92,007)	(111,202)
Effect of exchange rate changes on cash and cash equivalents	(312)	(458)	8
Net increase (decrease) in cash and cash equivalents	53,158	(17,297)	(6,341)
Cash and cash equivalents at beginning of period	73,032	90,329	96,670
Cash and cash equivalents at end of period	126,190	73,032	90,329
Supplemental disclosures of cash flow information:
Income tax payments, net	952	1,926	4,341
Supplemental schedule of non-cash investing and financing activities:
Capital expenditures incurred but not yet paid	235	854	434
Debt issuance costs incurred but not yet paid	$ 582	$ 0	$ 0