Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2023	Apr. 03, 2022
Cash flows from operating activities:
Net income	$ 25,615	$ 67,333
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	16,579	15,056
Depreciation of property, plant, and equipment	3,986	4,117
Amortization of intangible assets	942	840
Excess and obsolete inventory charges	788	379
Amortization of discounts or premiums on investments	700	1,402
Realized loss (gain) on sale of investments	0	36
Change in deferred income taxes	(10,656)	(3,891)
Accounts receivable	(18,455)	(24,700)
Unbilled revenue	(173)	2,144
Inventories	(5,338)	(23,900)
Prepaid expenses and other current assets	231	4,212
Accounts payable	(192)	708
Accrued expenses	(9,942)	(28,718)
Accrued income taxes	4,721	16,745
Deferred revenue and customer deposits	17,003	18,712
Other	1,744	(958)
Net cash provided by operating activities	27,553	49,517
Cash flows from investing activities:
Purchases of investments	(46,480)	(39,155)
Maturities and sales of investments	46,199	112,976
Purchases of property, plant, and equipment	(5,507)	(4,585)
Net cash provided by (used in) investing activities	(5,788)	69,236
Cash flows from financing activities:
Net payments from issuance of common stock under stock plans	(3,055)	3,594
Repurchase of common stock	(24,178)	(130,405)
Payment of dividends	(12,091)	(11,303)
Net cash provided by (used in) financing activities	(39,324)	(138,114)
Effect of foreign exchange rate changes on cash and cash equivalents	356	(1,031)
Net change in cash and cash equivalents	(17,203)	(20,392)
Cash and cash equivalents at beginning of period	181,374	186,161
Cash and cash equivalents at end of period	$ 164,171	$ 165,769