CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 50,700	$ 62,134
Short-term marketable securities	213,042	188,323
Accounts receivable, net of allowances for doubtful accounts of $734 and $525 in 2017 and 2016, respectively	17,192	6,528
Inventories	55,158	52,564
Prepaid expenses and other current assets	10,831	8,715
Total current assets	346,923	318,264
PROPERTY AND EQUIPMENT, net	114,855	95,296
INTANGIBLE ASSETS, net	26,871	31,502
GOODWILL	91,849	91,849
DEFERRED TAX ASSETS	19,086	11,342
OTHER ASSETS	24,899	6,157
Total assets	624,483	554,410
CURRENT LIABILITIES:
Accounts payable	38,474	29,727
Accrued payroll and related expenses	9,772	10,756
Taxes payable	1,227	729
Other accrued liabilities	4,895	2,734
Total current liabilities	54,368	43,946
LONG-TERM INCOME TAXES PAYABLE	2,817	2,639
DEFERRED TAX LIABILITIES	538	820
OTHER LIABILITIES	4,501	3,921
Total liabilities	62,224	51,326
COMMITMENTS AND CONTINGENCIES (Notes 11, 12 and 13)
STOCKHOLDERS’ EQUITY:
Common stock	29	28
Additional paid-in capital	192,074	172,875
Accumulated other comprehensive loss	(2,320)	(2,710)
Retained earnings	372,476	332,891
Total stockholders’ equity	562,259	503,084
Total liabilities and stockholders’ equity	$ 624,483	$ 554,410