Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 68,218,000	$ 47,653,000
Short-term marketable securities	39,028,000	33,201,000
Accounts receivable, net of allowance for doubtful accounts of $333 and $330 as of September 30, 2016 and December 31, 2015, respectively	37,261,000	36,125,000
Inventory	9,930,000	9,771,000
Prepaid expenses and other current assets	5,392,000	5,224,000
Income taxes receivable		6,028,000
Total current assets	159,829,000	138,002,000
Long-lived assets	142,722,000	125,475,000
Goodwill	28,916,000	28,916,000
Other intangible assets, net	2,817,000	3,337,000
Long-term marketable securities	68,387,000	64,789,000
Other long-term assets	1,374,000	517,000
Total assets	404,045,000	361,036,000
Current liabilities
Accounts payable	10,703,000	13,643,000
Accrued compensation	10,330,000	9,993,000
Accrued liabilities and other	3,612,000	2,626,000
Income taxes payable	541,000
Total current liabilities	25,186,000	26,262,000
Long-term deferred tax liabilities	4,247,000	4,240,000
Other long-term liabilities	3,795,000	2,889,000
Total liabilities	33,228,000	33,391,000
Shareholders' equity
Preferred stock, $0.001 par value, authorized 10,000,000 shares; issued and outstanding 0 shares as of each of September 30, 2016 and December 31, 2015
Common stock, $0.001 par value, authorized 150,000,000 shares; issued and outstanding 26,432,035 and 26,200,718 shares as of September 30, 2016 and December 31, 2015, respectively	26,000	26,000
Additional paid-in capital	210,226,000	198,835,000
Retained earnings	167,331,000	133,996,000
Accumulated other comprehensive loss	(6,766,000)	(5,212,000)
Total shareholders' equity	370,817,000	327,645,000
Total liabilities and shareholders' equity	$ 404,045,000	$ 361,036,000

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.