CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 144,246	$ 111,795
Short-term investments	194,331	234,294
Accounts receivable	8,708	10,727
Inventory	5,574	3,843
Other current assets	2,472	1,645
Total current assets	355,331	362,304
PROPERTY AND EQUIPMENT, net of accumulated depreciation of $19,154 and $18,735	12,268	10,884
ACQUIRED TECHNOLOGY, net of accumulated amortization of $17,014 and $17,000	376	391
INVESTMENTS	971
OTHER ASSETS	284	299
TOTAL ASSETS	369,230	373,878
CURRENT LIABILITIES:
Accounts payable	4,600	4,776
Accrued expenses	6,506	9,020
Deferred revenue	5,897	5,534
Other current liabilities	284	187
Total current liabilities	17,287	19,517
DEFERRED REVENUE	3,636	3,874
RETIREMENT PLAN BENEFIT LIABILITY	8,401	8,260
Total liabilities	29,324	31,651
COMMITMENTS AND CONTINGENCIES (Note 11)
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 $1,500,000)	2	2
Common Stock, par value $0.01 per share, 100,000,000 shares authorized, 46,336,765 and 46,113,296 shares issued and outstanding at March 31, 2012 and December 31, 2011, respectively	463	461
Additional paid-in capital	560,346	561,492
Accumulated deficit	(215,092)	(213,871)
Accumulated other comprehensive loss	(5,813)	(5,857)
Total shareholders' equity	339,906	342,227
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 369,230	$ 373,878