Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014
Cash flows from operating activities:
Net income	$ 65,344	$ 50,026
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	12,063	14,640
Amortization	5,715	6,864
Stock-based compensation	10,494	10,961
Asset impairments and write-offs of intangible assets	0	282
Other	(116)	0
Income taxes payable (receivable), net	6,547	(1,691)
Deferred income taxes	(4,785)	(2,411)
Decrease (increase), net of acquisitions, in:
Receivables, net	9,980	(28,932)
Inventories	(19,942)	(18,243)
Other assets	4,329	710
Increase (decrease), net of acquisitions, in:
Accounts payable	218	10,411
Accrued payroll liabilities	584	(4,574)
Accrued warranty reserves	590	(88)
Deferred revenue	6,412	4,156
Accrued restructuring, reorganization, relocation and severance	(6,894)	1,354
Other liabilities	(1,555)	959
Net cash provided by operating activities	88,984	44,424
Cash flows from investing activities:
Decrease (increase) in restricted cash	4,392	(3,154)
Acquisition of property, plant and equipment	(7,869)	(23,322)
Payments for acquisitions, net of cash acquired	(5,377)	(65,049)
Purchase of investments in marketable securities	(48,240)	(133,213)
Redemption of investments in marketable securities	62,679	105,267
Payments to Acquire Intangible Assets	(1,772)	(499)
Net cash provided by (used in) investing activities	3,813	(119,970)
Cash flows from financing activities:
Dividends paid on common stock	(20,877)	(10,129)
Withholding taxes paid on issuance of vested restricted stock units	(2,427)	(1,331)
Proceeds from exercise of stock options and employee stock purchases	7,873	7,880
Excess tax benefit for share based payment arrangements	879	2,011
Repurchases of common stock	(30,224)	(30,479)
Net cash used in financing activities	(44,776)	(32,048)
Effect of exchange rate changes	(15,334)	(4,204)
Increase (decrease) in cash and cash equivalents	32,687	(111,798)
Cash and cash equivalents:
Beginning of period	300,507	384,170
End of period	333,194	272,372
Supplemental Cash Flow Information:
Cash paid for income taxes, net	10,597	9,883
Cash paid for interest	145	196
Increase in fixed assets related to transfers from inventories	4,077	2,657
Dividends declared but not paid	12,479	10,564
Accrued purchases of plant and equipment	443	4,619
Accrued repurchases of common stock	$ 1,271	$ 0