Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 268,628	$ 342,211
Short-term investments	347,374	335,783
Accounts receivable, less allowances of $1,750	31,029	28,079
Deferred tax assets	52,573	53,990
Prepaid and other current assets	6,239	8,824
Total current assets	705,843	768,887
NON-CURRENT ASSETS:
PROPERTY AND EQUIPMENT, NET	7,229	7,997
PATENTS, NET	140,245	137,963
DEFERRED TAX ASSETS	51,550	54,110
OTHER NON-CURRENT ASSETS, NET	27,550	28,011
Total non-current assets	226,574	228,081
TOTAL ASSETS	932,417	996,968
CURRENT LIABILITIES:
Current portion of long-term debt	104	180
Accounts payable	4,274	7,110
Accrued compensation and related expenses	11,229	14,129
Deferred revenue	108,212	134,087
Taxes payable	4,432	3,265
Divided payable	4,469	4,570
Other accrued expenses	8,838	9,812
Total current liabilities	141,558	173,153
LONG-TERM DEBT	194,427	192,529
NON-CURRENT LIABILITIES
LONG-TERM DEFERRED REVENUE	140,681	153,953
OTHER LONG-TERM LIABILITIES	2,479	5,651
TOTAL LIABILITIES	479,145	525,286
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS’ EQUITY:
Preferred Stock, $0.10 par value, 0 and 14,399 shares authorized 0 shares issued and outstanding	0	0
Common Stock, $0.01 par value, 100,000 shares authorized, 68,968 and 68,602 shares issued and 45,398 and 45,032 shares outstanding	693	691
Additional paid-in capital	573,708	573,950
Retained earnings	473,145	466,727
Accumulated other comprehensive income	298	(439)
Stockholders' Equity before Treasury Stock	1,047,844	1,040,929
Treasury stock, 23,570 shares of common held at cost	594,572	569,247
Total shareholders’ equity	453,272	471,682
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 932,417	$ 996,968