CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 343,272	$ 258,874
Short-term marketable securities	148,067	190,318
Accounts receivable, net	42,257	35,910
Inventories	90,509	102,878
Prepaid expenses and other current assets	18,207	13,252
Total current assets	642,312	601,232
PROPERTY AND EQUIPMENT, net	168,712	166,188
INTANGIBLE ASSETS, net	11,474	12,506
GOODWILL	91,849	91,849
DEFERRED TAX ASSETS	1,892	3,339
OTHER ASSETS	28,480	28,225
Total assets	944,719	903,339
CURRENT LIABILITIES:
Accounts payable	38,172	34,712
Accrued payroll and related expenses	13,339	14,806
Taxes payable	856	902
Other accrued liabilities	10,160	12,106
Total current liabilities	62,527	62,526
LONG-TERM INCOME TAXES PAYABLE	14,033	15,588
OTHER LIABILITIES	14,336	14,814
Total liabilities	90,896	92,928
COMMITMENTS AND CONTINGENCIES (Notes 11, 12 and 13)
STOCKHOLDERS' EQUITY:
Common stock	29	28
Additional paid-in capital	203,051	190,920
Accumulated other comprehensive loss	(2,836)	(2,163)
Retained earnings	653,579	621,626
Total stockholders' equity	853,823	810,411
Total liabilities and stockholders' equity	$ 944,719	$ 903,339