CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2016
Cash flows provided by operating activities:
Net income	$ 25,381	$ 128,046	$ 84,172	$ 76,609
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, plant and equipment	2,702	11,426	7,011	3,763
Amortization of intangible assets	57	1,193	144	84
Amortization of premium and accretion of discount on available-for-sale marketable securities	681	1,242	2,061	532
Stock-based compensation	6,600	30,618	17,564	9,089
Capital loss from disposal of equipment		445
Realized loss from sale of available-for-sale marketable securities		137
Realized gain from cash flow hedge	(317)	(31)	(994)	(169)
Changes in assets and liabilities:
Inventories	14,022	(20,178)	(15,690)	(7,356)
Prepaid expenses and other assets	(127)	(2,711)	(20,943)	10,814
Trade receivables, net	1,555	(60,514)	(38,139)	(37,271)
Deferred tax assets and liabilities, net	3,652	(7,093)	(5,455)	(6,380)
Trade payables, net	(14,464)	31,482	35,455	(32,200)
Employees and payroll accruals	2,996	4,583	9,394	3,278
Warranty obligations	7,183	41,878	20,436	19,313
Deferred revenues	1,335	37,041	14,106	8,578
Other liabilities	(2,235)	(8,485)	27,543	3,846
Net cash provided by operating activities	49,021	189,079	136,665	52,530
Cash flows from investing activities:
Business combinations, net of cash acquired		(94,737)
Purchase of property, plant and equipment	(11,025)	(38,608)	(21,382)	(15,690)
Purchase of intangible assets	(600)			(800)
Investment in short term bank deposits		(6,001)
Investment in available-for-sale marketable securities	(40,858)	(142,627)	(143,675)	(118,511)
Proceed from sales and maturities of available-for-sale marketable securities	32,782	129,345	80,269	6,350
Net cash used in investing activities	(19,701)	(152,628)	(84,788)	(128,651)
Cash flows from financing activities:
Repayment of bank loan		(3,786)
Issuance costs related to initial public offering				(194)
Proceeds from issuance of shares under stock purchase plan and upon exercise of stock-based awards	1,284	10,021	7,240	2,973
Purchase of Non-controlling interests		(14,190)
Net cash provided by financing activities	1,284	(7,955)	7,240	2,779
Increase (decrease) in cash, cash equivalents and restricted cash	30,604	28,496	59,117	(73,342)
Cash, cash equivalents and restricted cash at the beginning of the period	74,960	164,679	105,580	148,389
Effect of exchange rate differences on cash, cash equivalents and restricted cash	16	86	(18)	(87)
Cash, cash equivalents and restricted cash at the end of the period	105,580	193,261	164,679	74,960
Supplemental disclosure of non-cash investing activities:
Net change in accrued expenses and other accounts payable related to property and equipment additions			598	1,187
Supplemental disclosure of cash flow information:
Cash paid for taxes	$ 1,103	$ 15,368	$ 3,100	$ 1,178