Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013
Cash flows from operating activities:
Net income	$ 71,671	$ 85,400
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	22,379	17,442
Amortization	10,478	7,868
Stock-based compensation	17,456	13,316
Asset impairments, write-offs of intangible assets and other	322	17
Income taxes (receivable) payable, net	(4,010)	11,448
Deferred income taxes	(2,275)	(4,442)
Decrease (increase), net of acquisitions, in:
Receivables	(27,840)	(4,073)
Inventories	(26,772)	(8,544)
Other assets	(4,882)	990
Increase (decrease), net of acquisitions, in:
Accounts payable	9,655	14,865
Accrued payroll liabilities	(9,872)	(5,017)
Accrued warranty reserves	(288)	327
Deferred revenue	9,120	13,698
Accrued restructuring, reorganization, relocation and severance	6,709	(2,309)
Other liabilities	747	(742)
Net cash provided by operating activities	72,598	140,244
Cash flows from investing activities:
Increase in restricted cash	(3,034)	(8,176)
Acquisition of property, plant and equipment	(35,429)	(47,152)
Payments for acquisitions, net of cash acquired	(65,049)	(2,694)
Purchase of investments in marketable securities	(189,621)	(132,965)
Redemption of investments in marketable securities	175,424	119,349
Other	(736)	(2,366)
Net cash used in investing activities	(118,445)	(74,004)
Cash flows from financing activities:
Redemption of 2.875% convertible notes	0	(73)
Dividends paid on common stock	(20,619)	(11,173)
Withholding taxes paid on issuance of vested restricted stock units	(1,784)	(954)
Proceeds from exercise of stock options and employee stock purchases	10,628	9,081
Excess tax benefit for share based payment arrangements	2,096	1,169
Repurchases of common stock	(40,315)	0
Net cash used in financing activities	(49,994)	(1,950)
Effect of exchange rate changes	(15,888)	4,910
(Decrease) increase in cash and cash equivalents	(111,729)	69,200
Cash and cash equivalents:
Beginning of period	384,170	266,302
End of period	272,441	335,502
Supplemental Cash Flow Information:
Cash paid for income taxes, net	14,458	7,505
Cash paid for interest	261	1,627
Increase in fixed assets related to transfers with inventories	4,345	8,285
Dividends declared but not paid	10,461	5,011
Conversion of 2.875% convertible notes	0	88,937
Accrued purchases of plant and equipment	$ 986	$ 6,434
Convertible Subordinated Debt [Member]
Supplemental Cash Flow Information:
Convertible notes, stated interest rate	0.00%	2.875%