Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 181,769	$ 172,704
Short-term investments	177,255	204,577
Accounts receivable, net	58,889	55,214
Inventories	142,543	136,384
Other current assets	13,629	11,931
Total current assets	574,085	580,810
Property and equipment, net	205,497	150,001
Long-term investments	3,290	3,241
Goodwill	6,571	6,571
Deferred tax assets, net	16,779	16,830
Other long-term assets	41,987	35,979
Total assets	848,209	793,432
Current liabilities:
Accounts payable	27,259	22,678
Accrued compensation and related benefits	18,969	18,799
Other accrued liabilities	45,348	38,962
Total current liabilities	91,576	80,439
Income tax liabilities	34,375	34,375
Other long-term liabilities	42,007	38,525
Total liabilities	167,958	153,339
Commitments and contingencies
Stockholders' equity:
Common stock and additional paid-in capital, $0.001 par value; shares authorized: 150,000; shares issued and outstanding: 43,033 and 42,505, respectively	478,913	450,908
Retained earnings	202,378	194,728
Accumulated other comprehensive loss	(1,040)	(5,543)
Total stockholders’ equity	680,251	640,093
Total liabilities and stockholders’ equity	$ 848,209	$ 793,432