CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 103,275	$ 102,176
Marketable securities	382,802	305,488
Accounts receivable	35,198	44,039
Unbilled receivables	155,448	184,366
Inventories	11,554	10,086
Prepaids and other current assets	17,970	18,524
Total current assets	706,247	664,679
Intangible assets, net	45,624	54,900
Goodwill	183,222	183,465
Property, plant and equipment, net	50,858	44,714
Operating lease right-of-use assets	31,407	37,020
Deferred tax assets	5,350	4,574
Unbilled receivables, long-term	289,044	343,703
Other assets	4,895	5,931
Total assets	1,316,647	1,338,986
Current liabilities:
Accounts payable	14,016	9,549
Accrued salaries and benefits	16,170	20,291
Deferred revenue	10,841	11,947
Income taxes payable	20,044	19,142
Operating lease liabilities	4,463	6,357
Other current liabilities	17,924	18,893
Total current liabilities	83,458	86,179
Convertible notes	152,359	148,788
Long-term operating lease liabilities	37,626	39,889
Long-term income taxes payable	50,472	60,094
Deferred tax liabilities	14,724	13,846
Other long-term liabilities	12,818	19,272
Total liabilities	351,457	368,068
Commitments and contingencies (Notes 9, 11 and 15)
Stockholders’ equity:
Convertible preferred stock, $.001 par value: Authorized: 5,000,000 shares; Issued and outstanding: no shares at June 30, 2020 and December 31, 2019	0	0
Common stock, $.001 par value: Authorized: 500,000,000 shares; Issued and outstanding: 113,743,652 shares at June 30, 2020 and 112,131,352 shares at December 31, 2019	114	112
Additional paid-in capital	1,274,136	1,261,142
Accumulated deficit	(309,008)	(290,244)
Accumulated other comprehensive loss	(52)	(92)
Total stockholders’ equity	965,190	970,918
Total liabilities and stockholders’ equity	$ 1,316,647	$ 1,338,986