CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 79,899,000	$ 69,085,000
Restricted Cash, Current	1,422,000	1,663,000
Accounts receivable, net of allowances of $1,339 and $11,142 at December 31, 2018 and 2017, respectively	78,614,000	73,773,000
Inventories	26,568,000	29,166,000
Prepaid expenses	6,044,000	9,425,000
Contract with Customer, Asset, after Allowance for Credit Loss	18,579,000	19,494,000
Other current assets	2,366,000	6,125,000
Total current assets	213,492,000	208,731,000
Property, Plant and Equipment, Net	16,814,000	19,580,000
Goodwill	32,643,000	32,643,000
Long-term deferred tax assets, net	6,801,000	7,479,000
Other long-term assets	5,958,000	6,113,000
Total assets	305,138,000	304,293,000
Current liabilities:
Accounts payable	21,823,000	39,888,000
Accrued compensation and benefits	29,105,000	19,524,000
Accrued expenses and other current liabilities	42,264,000	36,759,000
Income taxes payable	1,664,000	1,945,000
Short-term debt	4,941,000	30,554,000
Deferred revenues	87,974,000	83,589,000
Total current liabilities	187,771,000	212,259,000
Long-term debt	202,759,000	199,034,000
Long-term deferred revenues	11,284,000	14,312,000
Operating Lease, Liability, Noncurrent	28,462,000	28,127,000
Operating Lease, Right-of-Use Asset	29,430,000	29,747,000
Other long-term liabilities	7,786,000	5,646,000
Total liabilities	438,062,000	459,378,000
Commitments and contingencies (Note J)
Stockholders' deficit:
Preferred stock, $0.01 par value, 1,000 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.01 par value, 100,000 shares authorized; 42,339 shares issued and 41,949 shares and 41,356 shares outstanding at December 31, 2018 and 2017, respectively	442,000	430,000
Additional paid-in capital	1,036,658,000	1,027,824,000
Accumulated deficit	(1,168,347,000)	(1,179,409,000)
Accumulated other comprehensive loss	(1,677,000)	(3,930,000)
Total stockholders' deficit	(132,924,000)	(155,085,000)
Total liabilities and stockholders' deficit	$ 305,138,000	$ 304,293,000