Consolidated Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2021	Apr. 04, 2020
Operating activities
Net earnings	$ 71,643	$ 27,384
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	42,146	41,520
(Gain) loss on disposal of property and equipment	(177)	(45)
Accretion of interest on convertible debt instruments	0	3,637
Inventory write-offs for obsolescence	4,784	5,643
Deferred income taxes	901	(3,517)
Loss on extinguishment of debt	0	2,920
Other	5,728	3,524
Net change in operating assets and liabilities	(67,703)	(46,588)
Net cash provided by operating activities	57,322	34,478
Investing activities
Capital expenditures	(28,527)	(24,328)
Proceeds from sale of property and equipment	200	53
Purchase of short-term investments	(12,853)	(35,463)
Maturity of short-term investments	29,519	0
Other investing activities	347	(1,507)
Net cash provided by (used in) investing activities	(11,314)	(61,245)
Financing activities
Repurchase of convertible debt instruments	(300)	(19,849)
Net proceeds (payments) on revolving credit lines	0	54,000
Net changes in short-term borrowings	0	85
Cash withholding taxes paid when shares withheld for vested equity awards	(1,963)	(1,991)
Net cash provided by (used in) financing activities	(16,020)	18,504
Effect of exchange rate changes on cash and cash equivalents	(6,015)	(5,167)
Net increase (decrease) in cash and cash equivalents	23,973	(13,430)
Cash and cash equivalents at beginning of period	619,874	694,133
Cash and cash equivalents at end of period	643,847	680,703
Common Stock [Member]
Operating activities
Net earnings	0	0
Financing activities
Dividends paid to common stockholders	(12,608)	(12,592)
Class B Convertible Common Stock [Member]
Operating activities
Net earnings	0	0
Financing activities
Dividends paid to common stockholders	$ (1,149)	$ (1,149)