Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets, Current [Abstract]
Cash and cash equivalents	$ 36,112	$ 80,386
Short-term investments	235,547	79,666
Accounts receivable, net of allowances of $4	56,532	5,924
Inventory	4,243	4,680
Prepaid expenses and other current assets	5,320	2,668
Total current assets	337,754	173,324
Property and equipment, net of accumulated depreciation and amortization of $61,741 and $60,006, respectively	14,047	15,865
Goodwill	44,543	44,543
Intangible assets	19,716	50,119
Other assets	1,655	285
Total assets	417,715	284,136
Liabilities, Current [Abstract]
Accounts payable	12,178	12,052
Accrued liabilities	42,151	21,245
Current portion of deferred revenue	0	2,339
Current portion of long-term debt, net of deferred financing costs	11,012	1,115
Total current liabilities	65,341	36,751
Deferred revenue, net of current portion	0	23,651
Long-term debt, net of deferred financing costs	234,171	243,887
Deferred tax liabilities	0	6,014
Other long-term liabilities	1,102	238
Total liabilities	300,614	310,541
Commitments and contingencies
Stockholders' Equity (Deficit):
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; 106,679 and 106,162 shares issued, respectively	106	106
Additional paid-in capital	1,462,172	1,447,954
Accumulated deficit	(1,341,444)	(1,471,577)
Accumulated other comprehensive gain (loss)	84	(12)
Treasury stock, at cost, 407 and 236 shares, respectively	(3,817)	(2,876)
Total stockholders' equity (deficit)	117,101	(26,405)
Total liabilities and equity (deficit)	$ 417,715	$ 284,136