CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 235,541	$ 211,022
Short-term investments	361,515	304,323
Accounts receivable	65,774	43,129
Inventory	57,771	70,000
Other current assets	10,415	6,366
Total current assets	731,016	634,840
PROPERTY AND EQUIPMENT, net of accumulated depreciation of $53,900 and $44,943	86,266	69,739
ACQUIRED TECHNOLOGY, net of accumulated amortization of $127,323 and $111,890	95,919	110,951
OTHER INTANGIBLE ASSETS, net of accumulated amortization of $4,420 and $3,384	12,420	13,456
GOODWILL	15,535	15,535
INVESTMENTS	5,000
DEFERRED INCOME TAXES	26,437	24,377
OTHER ASSETS	89,957	64,526
TOTAL ASSETS	1,062,550	933,424
CURRENT LIABILITIES:
Accounts payable	9,217	10,532
Accrued expenses	35,360	36,057
Deferred revenue	91,188	80,782
Other current liabilities	12,627	5,811
Total current liabilities	148,392	133,182
DEFERRED REVENUE	50,495	41,785
RETIREMENT PLAN BENEFIT LIABILITY	46,007	44,055
OTHER LIABILITIES	31,089	23,896
Total liabilities	275,983	242,918
COMMITMENTS AND CONTINGENCIES (Note 15)
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, 48,847,733 and 48,681,524 shares issued, and 47,482,085 and 47,319,887 shares outstanding, at September 30, 2019 and December 31, 2018, respectively	488	487
Additional paid-in capital	614,194	617,334
Retained earnings	227,286	129,552
Accumulated other comprehensive loss	(14,119)	(16,234)
Treasury stock, at cost (1,365,648 and 1,361,637 shares at September 30, 2019 and December 31, 2018, respectively)	41,284	40,635
Total shareholders’ equity	786,567	690,506
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 1,062,550	$ 933,424