Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 57,181	$ 66,392
Available-for-sale securities	66,361	159,943
Accounts receivable, net	11,071	12,187
Inventories	22,259	17,712
Prepaid expenses and other current assets	6,399	7,178
Total current assets	163,271	263,412
Property and equipment, net	445	542
Intangible and other non-current assets	141,545	1,014
Total assets	305,261	264,968
Current liabilities:
Accounts payable	4,345	10,072
Accrued and other liabilities	26,879	21,475
Deferred revenue	1,897	2,075
Less current portion		5,147
Total current liabilities	33,121	38,769
Long-term debt, net of current portion	295,498	230,536
Deferred revenue, net of current portion	4,243	4,674
Non-current accrued and other liabilities	283	327
Total liabilities	333,145	274,306
Commitments and contingencies
Stockholders' equity
Preferred stock; $1.00 par value; 5,000 shares authorized; no shares issued and outstanding at June 30, 2018 and December 31, 2017	0	0
Common stock; $.001 par value; 200,000 shares authorized; 106,187 and 105,977 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	106	105
Additional paid-in capital	839,310	834,730
Accumulated other comprehensive loss	(508)	(608)
Accumulated deficit	(866,792)	(843,565)
Total stockholders' deficit	(27,884)	(9,338)
Total liabilities and stockholders' deficit	$ 305,261	$ 264,968