Condensed 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	$ 185,083	$ 142,604
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	52,832	41,873
Amortization	62,122	69,495
Stock-based compensation	31,873	27,227
Provision for excess and obsolete inventory	21,505	9,616
Deferred taxes	(8,747)	(19,211)
Contingent consideration fair value adjustment	(630)
Tax benefit related to stock options and restricted stock units	(1,726)	(807)
Retirement plans actuarial gains		(1,359)
Impairment loss on property, plant and equipment		1,074
Other	2,110	1,088
Changes in operating assets and liabilities:
Accounts receivable	(163,670)	(55,963)
Inventories	38,267	34,194
Prepayments and other assets	47,784	(26,312)
Accounts payable and other accrued expenses	29,109	(17)
Deferred revenue and customer advances	14,266	(9,249)
Retirement plans contributions	(3,281)	(3,569)
Accrued income taxes	10,208	13,750
Net cash provided by operating activities	317,105	224,434
Cash flows from investing activities:
Purchases of property, plant and equipment	(146,352)	(82,925)
Purchases of marketable securities	(844,056)	(658,564)
Proceeds from maturities of marketable securities	495,565	401,901
Proceeds from sales of marketable securities	236,060	332,968
Proceeds from life insurance	4,391
Net cash used for investing activities	(254,392)	(6,620)
Cash flows from financing activities:
Issuance of common stock under employee stock purchase and stock options plans	21,030	16,778
Tax benefit related to stock options and restricted stock units	1,726	807
Payments of dividend	(24,428)
Payments of long-term debt	(190,975)	(1,063)
Payments of contingent consideration		(388)
Net cash (used for) provided by financing activities	(192,647)	16,134
(Decrease) increase in cash and cash equivalents	(129,934)	233,948
Cash and cash equivalents at beginning of period	341,638	338,920
Cash and cash equivalents at end of period	$ 211,704	$ 572,868