Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets
Cash and cash equivalents	$ 27,929	$ 36,759
Short-term marketable securities	35,695	25,137
Accounts receivable, net of allowance for doubtful accounts of $142 and $154 as of March 31, 2013 and December 31, 2012, respectively	17,468	15,791
Inventory	4,717	4,619
Prepaid expenses and other current assets	4,774	5,364
Income taxes receivable	3,203	1,877
Deferred tax assets	446	609
Total current assets	94,232	90,156
Property and equipment, net	45,629	45,316
Long-term marketable securities	48,877	36,965
Other assets	262	285
Total assets	189,000	172,722
Current liabilities
Accounts payable	5,759	4,758
Accrued compensation	7,468	5,995
Accrued liabilities and other	574	513
Current portion of long-term debt obligations	209	273
Total current liabilities	14,010	11,539
Long-term deferred tax liabilities	3,346	3,346
Long-term debt obligations	287	356
Other long-term liabilities	728	782
Total liabilities	18,371	16,023
Shareholders' equity
Preferred stock, $0.001 par value, authorized 10,000,000 shares; issued and outstanding 0 shares as of March 31, 2013 and December 31, 2012, respectively
Common stock, $0.001 par value, authorized 150,000,000 shares; issued and outstanding 25,170,856 and 24,803,640 shares as of March 31, 2013 and December 31, 2012, respectively	26	25
Additional paid in capital	153,581	147,032
Retained earnings	18,857	10,570
Accumulated other comprehensive income (loss)	(1,835)	(928)
Total shareholders' equity	170,629	156,699
Total liabilities and shareholders' equity	$ 189,000	$ 172,722