CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 50,485	$ 79,899
Restricted cash	1,422	1,422
Accounts receivable, net of allowances	58,125	78,614
Inventories	22,215	26,568
Prepaid expenses	6,766	6,044
Contract assets	22,612	18,579
Other current assets	2,335	2,366
Total current assets	163,960	213,492
Property and equipment, net	15,211	16,814
Goodwill	32,643	32,643
Right of use assets	25,202	29,430
Deferred tax assets, net	5,413	6,801
Other long-term assets	6,462	5,958
Total assets	248,891	305,138
Current liabilities:
Accounts payable	22,413	21,823
Accrued compensation and benefits	26,320	29,105
Accrued expenses and other current liabilities	34,511	42,264
Income taxes payable	1,447	1,664
Less: current portion	9,159	4,941
Deferred revenues	76,658	87,974
Total current liabilities	170,508	187,771
Long-term debt	162,990	202,759
Long-term deferred revenues	10,109	11,284
Long-term lease liabilities	24,466	28,462
Other long-term liabilities	7,249	7,786
Total liabilities	375,322	438,062
Commitments and contingencies (Note 7)
Stockholders' deficit:
Common stock, par value $0.01; authorized: 100,000 shares; issued: 45,693 shares at September 30, 2021 and 44,420 shares at December 31, 2020; outstanding: 45,281 shares at September 30, 2021 and 44,420 shares at December 31, 2020	454	442
Treasury stock	(11,169)	0
Additional paid-in capital	1,030,116	1,036,658
Accumulated deficit	(1,142,175)	(1,168,347)
Accumulated other comprehensive loss	(3,657)	(1,677)
Total stockholders' deficit	(126,431)	(132,924)
Total liabilities and stockholders' deficit	$ 248,891	$ 305,138