Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 172,704	$ 82,759
Short-term investments	204,577	216,331
Accounts receivable, net	55,214	38,037
Inventories	136,384	99,281
Other current assets	11,931	12,762
Total current assets	580,810	449,170
Property and equipment, net	150,001	144,636
Long-term investments	3,241	5,256
Goodwill	6,571	6,571
Acquisition-related intangible assets, net	111	951
Deferred tax assets, net	16,830	15,917
Other long-term assets	35,868	30,068
Total assets	793,432	652,569
Current liabilities:
Accounts payable	22,678	22,813
Accrued compensation and related benefits	18,799	15,597
Accrued liabilities	38,962	27,507
Total current liabilities	80,439	65,917
Income tax liabilities	34,375	31,621
Other long-term liabilities	38,525	33,024
Total liabilities	153,339	130,562
Commitments and contingencies (notes 13 and 14)
Stockholders' equity:
Common stock and additional paid-in capital, $0.001 par value; shares authorized: 150,000; shares issued and outstanding: 42,505 and 41,614, respectively	450,908	376,586
Retained earnings	194,728	143,608
Accumulated other comprehensive income (loss)	(5,543)	1,813
Total stockholders’ equity	640,093	522,007
Total liabilities and stockholders’ equity	$ 793,432	$ 652,569