Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 161,160	$ 260,629
Marketable securities	138,343	419,599
Prepaid expenses	25,628	25,718
Inventory	0	10,698
Receivables and other current assets	11,389	3,872
Current assets of discontinued operations	0	495,021
Total current assets	336,520	1,215,537
Marketable securities	97,114	61,445
Property, plant and equipment, net	9,706	17,373
Intangible assets, net	0	4,397
Goodwill	5,646	5,646
Operating lease right-of-use assets	91,532	67,563
Restricted cash and other non-current assets	53,277	65,727
Non-current assets of discontinued operations	0	343,564
Total assets	593,795	1,781,252
Current liabilities:
Accounts payable	25,883	13,811
Accrued expenses and other current liabilities	103,958	98,190
Operating lease liability, current portion	23,152	9,711
Current liabilities of discontinued operations	0	81,876
Total current liabilities	152,993	203,588
Operating lease liability, net of current portion	66,432	55,707
Other non-current liabilities	93	5,759
Non-current liabilities of discontinued operations	0	161,142
Total liabilities	219,518	426,196
Commitments and contingencies Note 11
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2021 and December 31, 2020	0	0
Common stock, $0.01 par value, 125,000 shares authorized; 71,115 and 66,432 shares issued and outstanding at December 31, 2021 and December 31, 2020, respectively	711	665
Additional paid-in capital	4,096,402	4,260,443
Accumulated other comprehensive loss	(2,911)	(5,505)
Accumulated deficit	(3,719,925)	(2,900,547)
Total stockholders' equity	374,277	1,355,056
Total liabilities and stockholders' equity	$ 593,795	$ 1,781,252