Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 327,214	$ 402,579
Marketable securities	779,246	982,725
Prepaid expenses	32,888	19,762
Receivables and other current assets	12,826	13,931
Total current assets	1,152,174	1,418,997
Marketable securities	131,506	506,123
Property, plant and equipment, net	151,176	246,622
Intangible assets, net	14,326	13,169
Goodwill	13,128	13,128
Operating lease right-of-use assets	185,885
Restricted cash and other non-current assets	79,229	44,805
Total assets	1,727,424	2,242,844
Current liabilities:
Accounts payable	42,995	17,831
Accrued expenses and other current liabilities	141,556	99,393
Operating lease liability, current portion	20,175
Deferred revenue, current portion	8,474	18,602
Collaboration research advancement, current portion	10,380	10,605
Total current liabilities	223,580	146,431
Deferred revenue, net of current portion	9,791	16,338
Collaboration research advancement, net of current portion	27,834	33,349
Contingent consideration	7,977	5,230
Operating lease liability, net of current portion	170,812
Financing lease obligation, net of current portion	0	153,319
Other non-current liabilities	2,437	3,107
Total liabilities	442,431	357,774
Commitments and contingencies Note 9
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2019 and December 31, 2018	0	0
Common stock, $0.01 par value, 125,000 shares authorized; 55,368 and 54,738 shares issued and outstanding at December 31, 2019 and December 31, 2018, respectively	554	547
Additional paid-in capital	3,568,184	3,386,958
Accumulated other comprehensive loss	(1,893)	(3,627)
Accumulated deficit	(2,281,852)	(1,498,808)
Total stockholders' equity	1,284,993	1,885,070
Total liabilities and stockholders' equity	$ 1,727,424	$ 2,242,844