CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 143,016	$ 115,924
Marketable securities	162,850	161,840
Accounts receivable	43,810	50,863
Unbilled Receivables, Current	170,287	176,613
Inventories	8,192	6,772
Prepaids and other current assets	16,857	15,738
Total current assets	545,012	527,750
Intangible Assets, Net	55,507	59,936
Goodwill	207,828	207,178
Property, plant and equipment, net	22,637	57,028
Operating Lease, Right-of-Use Asset	19,458	0
Deferred tax assets	4,411	4,435
Contract with Customer, Asset, Net, Noncurrent	459,148	497,003
Other assets	7,419	7,825
Total assets	1,321,420	1,361,155
Current liabilities:
Accounts payable	8,274	7,392
Accrued salaries and benefits	13,666	16,938
Contract with Customer, Liability, Current	15,774	19,374
Accrued Income Taxes, Current	16,364	16,390
Operating Lease, Liability, Current	9,351	0
Other current liabilities	5,847	9,191
Total current liabilities	69,276	69,285
Convertible notes, long-term	143,612	141,934
Long-term imputed financing obligation	0	36,297
Operating Lease, Liability, Noncurrent	12,308	0
Accrued Income Taxes, Noncurrent	73,365	77,280
Other long-term liabilities	22,972	24,247
Total liabilities	321,533	349,043
Commitments and contingencies (Notes 11 and 15)
Stockholders’ equity:
Convertible preferred stock, $.001 par value: Authorized: 5,000,000 shares Issued and outstanding: no shares at March 31, 2019 and December 31, 2018	0	0
Common stock, $.001 par value: Authorized: 500,000,000 shares Issued and outstanding: 110,396,011 shares at March 31, 2019 and 109,017,708 shares at December 31, 2018	110	109
Additional paid-in capital	1,234,846	1,226,588
Accumulated deficit	(226,401)	(204,294)
Accumulated other comprehensive loss	(8,668)	(10,291)
Total stockholders’ equity	999,887	1,012,112
Total liabilities and stockholders’ equity	$ 1,321,420	$ 1,361,155