Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 147,450	$ 159,317
Accounts receivable	15,306	19,329
Supplies	7,041	6,806
Prepaid expenses and other current assets	2,891	2,235
Total current assets	172,688	187,687
Property and equipment, net	8,640	8,933
Right-of-use assets - operating lease	8,339	8,808
Finite-lived intangible assets, net	62,471	65,019
Goodwill	2,725	2,725
Restricted cash	603	603
Other assets	1,271	1,437
Total assets	256,737	275,212
Current liabilities:
Accounts payable	2,224	2,328
Accrued liabilities	9,386	13,734
Current portion of operating lease liability	1,495	1,407
Total current liabilities	13,105	17,469
Long-term debt	801	694
Acquisition-related contingent consideration	5,948	6,088
Operating lease liability, net of current portion	10,736	11,506
Total liabilities	30,590	35,757
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized, no shares issued and outstanding as of June 30, 2020 and December 31, 2019	0	0
Common stock, $0.001 par value; 125,000,000 shares authorized, 50,446,104 and 49,625,341 shares issued and outstanding as of June 30, 2020 and December 31, 2019, respectively	50	50
Additional paid-in capital	495,523	486,090
Accumulated deficit	(269,426)	(246,685)
Total stockholders’ equity	226,147	239,455
Total liabilities and stockholders’ equity	$ 256,737	$ 275,212