CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 99,491	$ 134,137
Short-term marketable securities	130,275	94,451
Accounts receivable, net of allowances for doubtful accounts of $763 and $706 in 2019 and 2018, respectively	25,468	11,072
Inventories	89,197	80,857
Prepaid expenses and other current assets	15,571	11,915
Total current assets	360,002	332,432
PROPERTY AND EQUIPMENT, net	112,939	114,117
INTANGIBLE ASSETS, net	18,920	21,152
GOODWILL	91,849	91,849
DEFERRED TAX ASSETS	5,184	6,906
OTHER ASSETS	31,495	22,241
Total assets	620,389	588,697
CURRENT LIABILITIES:
Accounts payable	35,985	31,552
Accrued payroll and related expenses	12,825	12,131
Taxes payable	579	933
Other accrued liabilities	5,945	3,750
Total current liabilities	55,334	48,366
LONG-TERM INCOME TAXES PAYABLE	9,006	8,652
DEFERRED TAX LIABILITIES	153	216
OTHER LIABILITIES	12,031	4,391
Total liabilities	76,524	61,625
COMMITMENTS AND CONTINGENCIES (Notes 11, 12, 13 and 14)
STOCKHOLDERS’ EQUITY:
Common stock	28	28
Additional paid-in capital	134,443	126,164
Accumulated other comprehensive loss	(1,336)	(1,689)
Retained earnings	410,730	402,569
Total stockholders’ equity	543,865	527,072
Total liabilities and stockholders’ equity	$ 620,389	$ 588,697