Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 2,734	$ 6,588
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,965	10,818
Provision for losses on inventories	2,334	2,310
Stock-based compensation expense	2,269	2,214
Provision for doubtful accounts	15	35
Loss on disposal of property and equipment	61	58
Deferred income taxes	(8)	(1,326)
Increase (decrease) in cash, net of acquisition, due to changes in:
Accounts and notes receivable	(1,782)	(1,415)
Inventories	(2,363)	(1,278)
Prepaid expenses and other assets	(449)	(1,270)
Accounts payable	(330)	1,053
Accrued payroll and related expenses	(2,379)	(5,979)
Accrued expenses and other liabilities	(289)	1,112
Other long-term liabilities	(328)	295
Net cash provided by operating activities	7,450	13,215
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(3,951)	(3,732)
Restricted cash	(53)	11,460
Business acquisition, net of cash acquired		(8,939)
Refundable amounts related to business acquisition		(317)
Purchase of marketable securities	(2,346)	(1,293)
Proceeds from the sale of marketable securities	1,481	878
Net cash used in investing activities	(4,869)	(1,943)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of long-term debt and obligations under capital leases	(11,892)	(9,376)
Proceeds from short-term borrowings	1,599	3,280
Repayment of short-term borrowings	(876)	(14,853)
Proceeds from the issuance of common stock under employee plans	4,010	2,001
Tax withholding payments related to net share settlement of equity awards		(3,053)
Net cash used in financing activities	(7,159)	(22,001)
Impact of foreign exchange rate changes on cash balances	(343)	298
Net decrease in cash and cash equivalents	(4,921)	(10,431)
Cash and cash equivalents at beginning of period	88,767	55,701
Cash and cash equivalents at end of period	83,846	45,270
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	1,927	1,873
Cash paid during the period for income taxes, net	799	1,299
Property and equipment accrued in accounts payable	$ 178	$ 20