CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jul. 04, 2021	Jun. 28, 2020
Cash flows from operating activities:
Net income	$ 533,831	$ 365,098
Adjustments to reconcile net income from operations to net cash provided by operating activities:
Depreciation	45,848	38,305
Stock-based compensation	23,231	21,367
Amortization	19,343	26,234
Loss on convertible debt conversion	5,244
Provision for excess and obsolete inventory	3,625	9,637
Contingent consideration adjustment	(7,227)	19,239
Gains on investments	(4,650)	(469)
Deferred taxes	(800)	(7,163)
Retirement plans actuarial gains	(627)	(99)
Other	199	523
Changes in operating assets and liabilities, net of business acquired:
Accounts receivable	(372,698)	(331,040)
Inventories	19,908	(3,728)
Prepayments and other assets	(117,416)	(49,479)
Accounts payable and other liabilities	86,790	113,578
Deferred revenue and customer advances	15,189	28,655
Retirement plans contributions	(2,739)	(2,501)
Income taxes	(2,628)	37,842
Net cash provided by operating activities	244,423	265,999
Cash flows from investing activities:
Purchases of property, plant and equipment	(73,957)	(84,014)
Purchases of marketable securities	(398,086)	(299,548)
Proceeds from maturities of marketable securities	460,213	182,984
Proceeds from sales of marketable securities	116,112	26,661
Proceeds from life insurance		546
Purchase of investment and acquisition of businesses	(12,000)	149
Net cash provided by (used for) investing activities	92,282	(173,222)
Cash flows from financing activities:
Issuance of common stock under stock purchase and stock option plans	32,581	12,757
Repurchase of common stock	(196,584)	(88,465)
Payments of convertible debt principal	(66,828)
Dividend payments	(33,271)	(33,266)
Payments related to net settlement of employee stock compensation awards	(31,794)	(22,519)
Payments of contingent consideration		(8,852)
Net cash used for financing activities	(295,896)	(140,345)
Effects of exchange rate changes on cash and cash equivalents	(489)	(925)
Increase (decrease) in cash and cash equivalents	40,320	(48,493)
Cash and cash equivalents at beginning of period	914,121	773,924
Cash and cash equivalents at end of period	954,441	725,431
Non-cash investing activities:
Capital expenditures incurred but not yet paid	$ 4,503	$ 6,281