Consolidated Balance Sheets - USD ($) $ in Thousands	Jul. 04, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 217,037	$ 269,073
Current investments, amortized cost of $189,818 and $102,258 in 2021 and 2020, respectively, allowance for credit losses of $0 in 2021 and 2020	190,747	103,240
Accounts receivable, allowance for credit losses of $803 and $831 in 2021 and 2020, respectively	149,157	125,696
Unbilled revenue	1,788	5,632
Inventories	68,503	60,830
Prepaid expenses and other current assets	65,646	37,220
Total current assets	692,878	601,691
Non-current investments, amortized cost of $542,015 and $390,417 in 2021 and 2020, respectively, allowance for credit losses of $0 in 2021 and 2020	543,965	395,125
Property, plant, and equipment, net	76,972	79,173
Operating lease assets	21,277	22,582
Goodwill	242,906	244,078
Intangible assets, net	13,702	15,555
Deferred income taxes	425,618	434,704
Other assets	7,603	7,794
Total assets	2,024,921	1,800,702
Current liabilities:
Accounts payable	32,304	16,270
Accrued expenses	76,653	77,264
Accrued income taxes	11,644	9,379
Deferred revenue and customer deposits	76,445	21,274
Operating lease liabilities	7,888	8,110
Total current liabilities	204,934	132,297
Non-current operating lease liabilities	16,362	18,120
Deferred income taxes	306,355	314,952
Reserve for income taxes	15,227	14,257
Non-current accrued income taxes	40,963	48,915
Other liabilities	11,626	9,959
Total liabilities	595,467	538,500
Shareholders’ equity:
Preferred stock, $.01 par value – Authorized: 400 shares in 2021 and 2020, respectively, no shares issued and outstanding	0	0
Common stock, $.002 par value – Authorized: 300,000 shares in 2021 and 2020, respectively, issued and outstanding: 176,707 and 175,790 shares in 2021 and 2020, respectively	353	352
Additional paid-in capital	874,883	807,739
Retained earnings	593,290	487,912
Accumulated other comprehensive loss, net of tax	(39,072)	(33,801)
Total shareholders’ equity	1,429,454	1,262,202
Total liabilities and shareholders' equity	$ 2,024,921	$ 1,800,702