Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 26, 2015	Sep. 27, 2014
Cash flows from operating activities:
Net income (loss)	$ 2,794	$ (2,248)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	45,166	48,739
Stock-based compensation	17,994	16,334
Unrealized foreign exchange gain, net	(8,179)	(2,372)
Net amortization of premiums and accrued interest on investments	587	628
Asset impairments	252	770
Gain on disposal of property and equipment	(63)
Gain on investment securities and other investments	(64)	(86)
Accretion of discount on short-term and long-term obligations	560
Amortization of debt issuance costs	153	153
Gain on exit of lease agreement	(696)
Changes in operating assets and liabilities:
Accounts receivable, net	(6,855)	(934)
Inventories, net	5,103	(3,514)
Prepaid expenses and other current assets	2,306	4,072
Accounts payable and accrued liabilities	(9,732)	(6,699)
Deferred taxes and income taxes payable	7,480	8,608
Deferred income	(15)	(1,980)
Net cash provided by operating activities	56,791	61,471
Cash flows from investing activities:
Cash paid in connection with business acquisition		(10,000)
Purchases of property and equipment	(13,724)	(11,175)
Purchase of intangible assets	(4,072)	(1,167)
Redemption of short-term investments	28,131	4,920
Disposals of investment securities and other investments	40,446	37,936
Purchases of investment securities and other investments	(92,577)	(67,727)
Net cash used in investing activities	(41,796)	(47,213)
Cash flows from financing activities:
Installment payment in connection with previous business acquisition	(18,000)
Proceeds from credit facility	102,000	30,000
Repayment of credit facility	(72,000)	(60,000)
Proceeds from issuance of common stock	36,982	17,924
Repurchases of common stock	(102,108)	(11,496)
Net cash used in financing activities	(53,126)	(23,572)
Effect of exchange rate changes on cash and cash equivalents	(1,309)	(784)
Net decrease in cash and cash equivalents	(39,440)	(10,098)
Cash and cash equivalents, beginning of the period	112,570	100,038
Cash and cash equivalents, end of the period	73,130	89,940
Supplemental disclosures of cash flow information:
Cash paid for interest	(483)	(276)
Cash payments made for income taxes, net of refunds received	$ (827)	$ (747)