CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 269,073,000	$ 171,431,000
Current investments, amortized cost of $102,258 and $235,610 in 2020 and 2019, respectively, allowance for credit losses of $0 in 2020 and 2019	103,240,000	240,470,000
Accounts receivable, allowance for credit losses of $831 and $530 in 2020 and 2019, respectively	125,696,000	103,447,000
Unbilled revenue	5,632,000	4,782,000
Inventories	60,830,000	60,261,000
Prepaid expenses and other current assets	37,220,000	26,840,000
Total current assets	601,691,000	607,231,000
Non-current investments, amortized cost of $390,417 and $431,633 in 2020 and 2019, respectively, allowance for credit losses of $0 in 2020 and 2019	395,125,000	433,452,000
Property, plant, and equipment, net	79,173,000	89,443,000
Operating lease assets	22,582,000	17,522,000
Goodwill	244,078,000	243,445,000
Intangible Assets, Net (Excluding Goodwill)	15,555,000	39,490,000
Deferred income taxes	434,704,000	449,519,000
Other assets	7,794,000	5,833,000
Total assets	1,800,702,000	1,885,935,000
Current liabilities:
Accounts payable	16,270,000	17,866,000
Accrued expenses	77,264,000	52,199,000
Accrued income taxes	9,379,000	30,333,000
Deferred revenue and customer deposits	21,274,000	14,432,000
Operating lease liabilities	8,110,000	5,647,000
Total current liabilities	132,297,000	120,477,000
Non-current operating lease liabilities	18,120,000	12,326,000
Deferred income taxes	314,952,000	332,344,000
Reserve for income taxes	14,257,000	11,563,000
Non-current accrued income taxes	48,915,000	51,113,000
Other liabilities	9,959,000	2,402,000
Total liabilities	538,500,000	530,225,000
Commitments and contingencies (Note 11)
Shareholders’ equity:
Preferred stock, $.01 par value - Authorized: 400 shares in 2020 and 2019, respectively, no shares issued and outstanding	0	0
Common stock, $.002 par value – Authorized: 300,000 shares in 2020 and 2019, respectively, issued and outstanding: 175,790 and 172,440 shares in 2020 and 2019, respectively	352,000	345,000
Additional paid-in capital	807,739,000	639,372,000
Retained earnings	487,912,000	753,268,000
Accumulated other comprehensive loss, net of tax	(33,801,000)	(37,275,000)
Total shareholders’ equity	1,262,202,000	1,355,710,000
Total liabilities and shareholders' equity	$ 1,800,702,000	$ 1,885,935,000