Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 38,410	$ 202,989
Short-term investments	390,955	318,363
Accounts receivable, net of allowances of $4	1,018	911
Prepaid expenses and other current assets	9,071	10,137
Total current assets	439,454	532,400
Property and equipment, net of accumulated depreciation and amortization of $58,855 and $59,428, respectively	20,350	21,227
Goodwill	44,543	44,543
Other intangible assets	53,357	53,357
Other assets	430	433
Total assets	558,134	651,960
Current liabilities:
Accounts payable	28,225	19,725
Accrued liabilities	23,950	24,757
Current portion of deferred revenue	61,528	76,499
Current portion of long-term debt, net of deferred issuance costs	17,289	1,976
Total current liabilities	130,992	122,957
Deferred revenue, net of current portion	92,188	109,151
Long-term debt, net of deferred issuance costs	84,909	100,960
Deferred tax liabilities	18,675	18,675
Other long-term liabilities	14,037	14,367
Total liabilities	340,801	366,110
Commitments and contingencies
Equity:
Preferred stock, $.01 par value; 5,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $.001 par value; 225,000 shares authorized; 104,152 and 103,860 shares issued, respectively	104	104
Additional paid-in capital	1,402,190	1,397,646
Accumulated deficit	(1,181,929)	(1,108,934)
Accumulated other comprehensive gain (loss)	336	(219)
Treasury stock, at cost, 306 and 237 shares, respectively	(3,368)	(2,747)
Total equity	217,333	285,850
Total liabilities and equity	$ 558,134	$ 651,960