CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 101,638	$ 132,840
Short-term investments	391,972	287,446
Accounts receivable	43,207	52,355
Inventory	69,031	36,265
Other current assets	11,943	10,276
Total current assets	617,791	519,182
PROPERTY AND EQUIPMENT, net of accumulated depreciation of $42,425 and $36,368	67,467	56,450
ACQUIRED TECHNOLOGY, net of accumulated amortization of $106,755 and $91,312	116,086	131,529
OTHER INTANGIBLE ASSETS, net of accumulated amortization of $3,036 and $2,000	13,804	14,840
GOODWILL	15,535	15,535
INVESTMENTS		14,794
DEFERRED INCOME TAXES	13,910	27,022
OTHER ASSETS	39,151	604
TOTAL ASSETS	883,744	779,956
CURRENT LIABILITIES:
Accounts payable	13,330	13,774
Accrued expenses	31,790	35,019
Deferred revenue	69,143	14,981
Other current liabilities	16	50
Total current liabilities	114,279	63,824
DEFERRED REVENUE	40,684	23,902
RETIREMENT PLAN BENEFIT LIABILITY	34,937	33,176
OTHER LIABILITIES	18,337
Total liabilities	208,237	120,902
COMMITMENTS AND CONTINGENCIES (Note 13)
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, 48,672,538 and 48,476,034 shares issued, and 47,310,901 and 47,118,171 shares outstanding, at September 30, 2018 and December 31, 2017, respectively	487	485
Additional paid-in capital	613,310	611,063
Retained earnings	112,337	99,126
Accumulated other comprehensive loss	(9,994)	(11,464)
Treasury stock, at cost (1,361,637 and 1,357,863 shares at September 30, 2018 and December 31, 2017, respectively)	(40,635)	(40,158)
Total shareholders’ equity	675,507	659,054
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 883,744	$ 779,956