Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 21,412	$ 50,908
Short-term investments	410,481	383,513
Accounts receivable, net	6,970	4,478
Current deferred tax assets	20,586	19,334
Other current assets	20,218	17,277
Total current assets	479,667	475,510
Intangible assets, net	66,489	72,925
Long-term deferred tax assets	13,303	21,759
Other assets	6,419	6,929
Total assets	565,878	577,123
Current liabilities:
Accounts payable	1,364	3,509
Accrued legal fees	4,797	4,143
Accrued liabilities	7,815	16,157
Deferred revenue	10,295	10,217
Total current liabilities	24,271	34,026
Long-term deferred tax and other liabilities	$ 1,906	$ 1,738
Commitments and contingencies (Note 12)
Stockholders’ equity:
Preferred stock: $0.001 par value; 10,000 shares authorized and no shares issued and outstanding	$ 0	$ 0
Common stock: $0.001 par value; 150,000 shares authorized; 58,527 and 57,800 shares issued, respectively, and 52,115 and 52,840 shares outstanding, respectively	58	58
Additional paid-in capital	591,530	576,341
Treasury stock at cost; 6,412 and 4,960 shares of common stock at each period end, respectively	(163,577)	(106,231)
Accumulated other comprehensive loss	(507)	(333)
Retained earnings	112,197	71,524
Total stockholders’ equity	539,701	541,359
Total liabilities and stockholders’ equity	$ 565,878	$ 577,123