Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets
Cash and equivalents	$ 56,278	$ 49,345
Short term investments	89,698	94,856
Accounts receivable, net of allowance for doubtful accounts of $541 in 2017 and $535 in 2016	35,237	36,693
Inventories, net	18,823	17,420
Prepaid expenses	4,190	3,249
Other current assets	5,172	5,596
Total current assets	209,398	207,159
Property and equipment
Furniture and fixtures	5,676	5,547
Office equipment	13,281	13,028
Property and equipment, gross	18,957	18,575
Accumulated depreciation	(15,814)	(15,294)
Property and equipment, net	3,143	3,281
Intangible assets, net of accumulated amortization	44,361	46,549
Goodwill	54,706	54,409
Other assets	16,431	15,872
Total assets	328,039	327,270
Current liabilities
Accounts payable	7,437	8,915
Deferred revenue	38,102	36,364
Accrued wages and payroll taxes	12,572	10,894
Income taxes payable	1,680	4,594
Other accrued expenses	5,204	5,464
Deferred compensation	1,972	1,729
Total current liabilities	66,967	67,960
Other long-term liabilities	1,881	1,878
Deferred income taxes	1,000	853
Total liabilities	69,848	70,691
Stockholders' equity
Preferred stock: 500 shares authorized, none issued and outstanding at March 31, 2017 or December 31, 2016	0	0
Common stock: $.001 par value per share, 75,000 shares authorized; 40,198 and 40,097 shares issued and outstanding at March 31, 2017 and December 31, 2016, respectively	40	40
Additional paid-in capital	87,871	87,481
Accumulated income	179,124	178,551
Accumulated other comprehensive loss	(8,844)	(9,493)
Total stockholders' equity	258,191	256,579
Total liabilities and stockholders' equity	$ 328,039	$ 327,270

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.