Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 218,368	$ 334,944
Short-term investments	420,455	260,169
Accounts receivable, net	84,059	66,843
Inventories	175,223	157,062
Other current assets	24,325	22,980
Total current assets	922,430	841,998
Property and equipment, net	297,741	281,528
Goodwill	6,571	6,571
Deferred tax assets, net	17,668	18,556
Other long-term assets	63,782	59,838
Total assets	1,308,192	1,208,491
Current liabilities:
Accounts payable	57,235	38,169
Accrued compensation and related benefits	56,307	45,840
Other accrued liabilities	74,367	62,960
Total current liabilities	187,909	146,969
Income tax liabilities	37,062	37,062
Other long-term liabilities	61,644	57,873
Total liabilities	286,615	241,904
Commitments and contingencies
Stockholders’ equity:
Common stock and additional paid-in capital: $0.001 par value; shares authorized: 150,000; shares issued and outstanding: 45,737 and 45,267, respectively	699,359	657,701
Retained earnings	315,206	298,746
Accumulated other comprehensive income	7,012	10,140
Total stockholders’ equity	1,021,577	966,587
Total liabilities and stockholders’ equity	$ 1,308,192	$ 1,208,491