CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash and cash equivalents	$ 213,896	$ 311,993
Short-term investments	439,449	351,194
Accounts receivable	74,933	107,639
Inventory	165,635	134,160
Other current assets	38,244	20,948
Total current assets	932,157	925,934
PROPERTY AND EQUIPMENT, net of accumulated depreciation of $103,881 and $92,461	138,028	128,832
ACQUIRED TECHNOLOGY, net of accumulated amortization of $183,928 and $173,635	39,375	49,668
OTHER INTANGIBLE ASSETS, net of accumulated amortization of $8,273 and $7,565	9,015	9,711
GOODWILL	15,535	15,535
INVESTMENTS	200,142	168,076
DEFERRED INCOME TAXES	36,998	33,453
OTHER ASSETS	128,188	135,710
TOTAL ASSETS	1,499,438	1,466,919
CURRENT LIABILITIES:
Accounts payable	14,048	14,955
Accrued expenses	38,757	45,474
Deferred revenue	99,106	120,864
Other current liabilities	3,302	6,645
Total current liabilities	155,213	187,938
DEFERRED REVENUE	30,021	36,217
RETIREMENT PLAN BENEFIT LIABILITY	68,188	66,773
OTHER LIABILITIES	80,707	76,077
Total liabilities	334,129	367,005
COMMITMENTS AND CONTINGENCIES (Note 18)
SHAREHOLDERS' EQUITY:
Preferred Stock, par value $0.01 per share, 5,000,000 shares authorized, 200,000 shares of Series A Nonconvertible Preferred Stock issued and outstanding (liquidation value of $7.50 per share or $1,500)	2	2
Common Stock, par value $0.01 per share, 200,000,000 shares authorized, 49,115,444 and 49,065,924 shares issued, and 47,749,796 and 47,700,276 shares outstanding, at June 30, 2022 and December 31, 2021, respectively	491	491
Additional paid-in capital	666,087	658,728
Retained earnings	563,191	500,212
Accumulated other comprehensive loss	(23,178)	(18,235)
Treasury stock, at cost (1,365,648 shares at June 30, 2022 and December 31, 2021)	(41,284)	(41,284)
Total shareholders’ equity	1,165,309	1,099,914
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 1,499,438	$ 1,466,919