CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Statement [Abstract]
Net revenues	$ 92,062	$ 64,756	$ 252,084	$ 178,395	$ 248,069
Cost of revenues	22,900	18,949	63,820	57,020	80,048
Gross profit	69,162	45,807	188,264	121,375	168,021
Operating costs and expenses:
Research, development and clinical trials	18,766	13,074	55,262	35,540	50,574
Sales and marketing	23,830	19,124	69,871	56,455	77,663
General and administrative	22,711	18,855	64,198	54,388	73,456
Total operating costs and expenses	65,307	51,053	189,331	146,383	201,693
Operating income (loss)	3,855	(5,246)	(1,067)	(25,008)	(33,672)
Financial expenses (income), net	2,555	2,397	6,165	10,110	12,270
Income (loss) before income taxes	1,300	(7,643)	(7,232)	(35,118)	(45,942)
Income taxes	(630)	4,051	4,258	12,810	17,617
Net income (loss)	$ 1,930	$ (11,694)	$ (11,490)	$ (47,928)	$ (63,559)
Basic net income (loss) per ordinary share (in usd per share)	$ 0.02	$ (0.13)	$ (0.12)	$ (0.52)	$ (0.69)
Weighted average number of ordinary shares used in computing basic net income (loss) per share (in shares)	98,485,519	92,911,375	96,551,041	91,409,619	91,828,043
Diluted net income (loss) per ordinary share (in usd per share)	$ 0.02	$ (0.13)	$ (0.12)	$ (0.52)	$ (0.69)
Weighted average number of ordinary shares used in computing diluted net income (loss) per share (in shares)	107,604,578	92,911,375	96,551,041	91,409,619	91,828,043