CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 136,146	$ 102,176
Marketable securities	366,503	305,488
Accounts receivable	27,903	44,039
Unbilled receivables	135,897	184,366
Inventories	14,466	10,086
Prepaids and other current assets	15,907	18,524
Total current assets	696,822	664,679
Intangible assets, net	36,487	54,900
Goodwill	183,222	183,465
Property, plant and equipment, net	57,693	44,714
Operating lease right-of-use assets	28,708	37,020
Deferred tax assets	4,353	4,574
Unbilled receivables, long-term	232,056	343,703
Other assets	4,535	5,931
Total assets	1,243,876	1,338,986
Current liabilities:
Accounts payable	8,993	9,549
Accrued salaries and benefits	23,326	20,291
Deferred revenue	10,198	11,947
Income taxes payable, short-term	20,064	19,142
Operating lease liabilities	4,724	6,357
Other current liabilities	18,559	18,893
Total current liabilities	85,864	86,179
Convertible notes, long-term	156,031	148,788
Long-term operating lease liabilities	34,305	39,889
Long-term income taxes payable	41,333	60,094
Deferred tax liabilities	14,336	13,846
Other long-term liabilities	6,894	19,272
Total liabilities	338,763	368,068
Commitments and contingencies (Notes 10, 13 and 20)
Stockholders’ equity:
Convertible preferred stock, $.001 par value: Authorized: 5,000,000 shares; Issued and outstanding: no shares at December 31, 2020 and December 31, 2019	0	0
Common Stock, $.001 par value: Authorized: 500,000,000 shares; Issued and outstanding: 111,697,994 shares at December 31, 2020 and 112,131,352 shares at December 31, 2019	112	112
Additional paid in capital	1,270,426	1,261,142
Accumulated deficit	(365,344)	(290,244)
Accumulated other comprehensive loss	(81)	(92)
Total stockholders’ equity	905,113	970,918
Total liabilities and stockholders’ equity	$ 1,243,876	$ 1,338,986