EQUITY (Tables)
 12 Months Ended
Dec. 31, 2016
Stockholders' Equity Note [Abstract]  
Schedule of summary of equity activity
​ ​ ​
Ordinary 
Shares
 ​ ​
Class A 
Ordinary 
Shares
 ​ ​
Class B 
Ordinary 
Shares
 ​ ​
Class C 
Ordinary 
Shares
 ​ ​
Class D 
Ordinary 
Shares
 ​ ​
Class E 
Ordinary 
Shares
 ​ ​
Class F1 
Ordinary 
Shares
 ​ ​
Class F2 
Ordinary 
Shares
 ​ ​
Ordinary 
Shares (with 
liquidation 
preference)
 ​
​ ​ ​
Number of shares – issued and outstanding
 ​
Balance, as of January 1, 2014
 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 32,070,835 ​ ​ ​ ​ ​ 6,703,520 ​ ​ ​ ​ ​ 3,390,490 ​ ​ ​ ​ ​ 32,164,955 ​ ​ ​ ​ ​ 11,749,700 ​ ​ ​ ​ ​ 14,326,650 ​ ​ ​ ​ ​ 41,547,280 ​ ​ ​ ​ ​ 60,559,715 ​ ​
Exercise of options – prior to IPO
 ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ 1,463,051 ​ ​
Conversion upon IPO closing
 ​ ​ ​ ​ 203,976,196 ​ ​ ​ ​ ​ (32,070,835) ​ ​ ​ ​ ​ (6,703,520) ​ ​ ​ ​ ​ (3,390,490) ​ ​ ​ ​ ​ (32,164,955) ​ ​ ​ ​ ​ (11,749,700) ​ ​ ​ ​ ​ (14,326,650) ​ ​ ​ ​ ​ (41,547,280) ​ ​ ​ ​ ​ (62,022,766) ​ ​
IPO
 ​ ​ ​ ​ 8,325,000 ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​
Exercise of options – commencing IPO
 ​ ​ ​ ​ 2,252,865 ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​
Balance, as of December 31, 2014
 ​ ​ ​ ​ 214,554,061 ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​
Exercise of options and vesting of RSUs
 ​ ​ ​ ​ 4,293,369 ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​
Balance, as of December 31, 2015
 ​ ​ ​ ​ 218,847,430 ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​
Exercise of options and vesting of RSUs
 ​ ​ ​ ​ 2,890,584 ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ ​
Balance, as of December 31, 2016
 ​ ​ ​ ​ 221,738,014 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
​
Schedule of information regarding outstanding and exercisable options
 
Exercise price
  
Outstanding
  
Exercisable
 
 
(US $)
  
Number
  
Weighted average
remaining
contractual life
(in years)
  
Number
  
Weighted average
remaining
contractual life
(in years)
 
 
0.096 – 2.991
    119,655     3.35     84,655     3.48  
 
3.7
    5,882,283     2.84     5,734,118     2.85  
 
6.98
    13,146,059     4.06     12,227,784     4.03  
 
25 – 46.88
    5,384,240     6.35     238,356     5.06  
 
55.63 – 59.33
    4,410,700     5.68     1,470,350     5.68  
      28,942,937     4.48     19,755,263     3.82  
 
Schedule of options granted to employees, directors and service providers
     
Number
    
Weighted
average
exercise price
    
Aggregated
intrinsic value(1)
  
                 
$
    
U.S. dollars
in thousands
  
Options outstanding at beginning of year
         27,188,687           14.85                
Changes during the year:        
Granted(2)
         4,576,500           45.91                
Exercised
         (2,746,100)           2.88                
Forfeited
         (76,150)           18.90                
Options outstanding at end of year
         28,942,937           20.82           623,550    
Options exercisable at year-end
         19,755,263           10.05           583,398    
 
 
(1)    The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the closing stock price of  $38.12 of the Company’s ordinary share on December 31, 2016. This represents the potential pre-tax amount receivable by the option holders had all option holders exercised their options as of such date.
 
(2)    On August 15, 2016 the Company granted the Company’s founders, who are also shareholders, 4,000,000 options, exercisable into the same amount of the Company’s ordinary shares, at an exercise price of  $46.88 per share, which are subject to graded vesting over four years.
 
 
Schedule of RSUs activity
   
Number
  
Weighted average
grant date fair value ($)
 
Outstanding at beginning of year
    281,181     41.0  
Changes during the year:   
Granted
    205,962     38.96  
Vested
    (144,484)     40.33  
Forfeited
    (16,372)     41.07  
Outstanding at end of year
    326,287     40.01  
 
Schedule of assumptions used for the estimation of the fair value of options granted using the Black-Scholes option pricing model
   
Year ended December 31,
 
   
2016
  
2015
  
2014
 
Risk-free interest rate
  
0.93% – 1.57% 
  
0.75% – 2.01% 
  
0.7% – 2.17% 
 
Expected option term
  
3.28 – 6.67 years 
  
2.16 – 6.95 years 
  
3.82 – 7.27 years 
 
Expected price volatility
  
40% – 44% 
  
35% – 53% 
  
36% – 55% 
 
Dividend yield
  
0% 
  
0% 
  
0% 
 
Weighted average fair value at the date of grant
  
$17.09 
  
$16.05 
  
$7.28 
 
Schedule of share-based compensation expenses
   
Year ended December 31,
 
   
2016
  
2015
  
2014
 
   
U.S. dollars in thousands
 
Cost of revenues
    46     26     27  
Research and development, net
    12,216     8,016     6,130  
Sales and marketing
    706     1,277     5,201  
General and administrative
    52,634     35,650     65,495  
Total stock-based compensation
    65,602     44,969     76,853  
 
Schedule of computation of basic and diluted net earnings (losses) per share
     
Year ended December 31,
  
     
2016
    
2015
    
2014
  
     
U.S. dollars in thousands, except per share data
  
Numerator for basic and diluted net earnings (losses) per share:
        
Net income (loss) applicable to ordinary shares
         108,370           68,450           (30,084)    
Weighted average shares outstanding:        
Denominator for basic net earnings per share
         220,124           217,362           107,942    
Effect of dilutive securities:        
Employee and Non-Employee stock options and unvested RSUs
         17,894           20,495           —    
Denominator for diluted net earnings per share
         238,018           237,857           107,942    
Basic net earnings (losses) per share
         0.49           0.31           (0.28)    
Diluted net earnings (losses) per share
         0.46           0.29           (0.28)