Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 142,604	$ 233,592
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	41,873	39,812
Amortization	69,495	67,366
Stock-based compensation	27,227	30,634
Provision for excess and obsolete inventory	9,616	16,408
Deferred taxes	(19,211)	7,076
Non cash charge for the sale of inventories revalued at the date of acquisition		6,089
Contingent consideration adjustment		(8,373)
Tax benefit related to stock options and restricted stock units	(807)	(7,600)
Retirement plans actuarial (gains) losses	(1,359)	4,991
Impairment loss on property, plant and equipment	1,074
Other	83	(2,359)
Changes in operating assets and liabilities:
Accounts receivable	(55,963)	(76,134)
Inventories	34,194	25,070
Prepayments and other assets	(26,312)	7,278
Accounts payable and other accrued expenses	496	(17,600)
Deferred revenue and customer advances	(9,762)	(10,651)
Retirement plans contributions	(3,569)	(3,679)
Accrued income taxes	13,750	50,313
Net cash provided by operating activities	223,429	362,233
Cash flows from investing activities:
Purchases of property, plant and equipment	(82,925)	(91,132)
Purchases of marketable securities	(657,188)	(510,157)
Proceeds from maturities of marketable securities	401,901	156,422
Proceeds from sales of marketable securities	332,597	14,250
Net cash used for investing activities	(5,615)	(430,617)
Cash flows from financing activities:
Issuance of common stock under employee stock option and stock purchase plans	16,778	17,959
Tax benefit related to stock options and restricted stock units	807	7,600
Payments of long-term debt	(1,063)	(1,246)
Payments of contingent consideration	(388)	(43,973)
Net cash provided by (used) for financing activities	16,134	(19,660)
Increase (decrease) in cash and cash equivalents	233,948	(88,044)
Cash and cash equivalents at beginning of period	338,920	573,736
Cash and cash equivalents at end of period	$ 572,868	$ 485,692