Quarterly report pursuant to Section 13 or 15(d)

Assets and Liabilities Measured at Fair Value (Details)

v3.7.0.1
Assets and Liabilities Measured at Fair Value (Details) - USD ($)
 1 Months Ended
Dec. 31, 2016
Apr. 30, 2017
Mar. 31, 2017
Zero-strike call option | Call Option      
Assets and Liabilities Measured at Fair Value      
Derivative underlying share amount $ 704,908 $ 600,242  
Derivative premium paid 47,900,000 $ 50,000,000  
Total      
Assets and Liabilities Measured at Fair Value      
Derivative Asset 49,019,000    
Total | Recurring      
Assets and Liabilities Measured at Fair Value      
Cash equivalents 198,011,000   $ 241,185,000
Quoted prices in active markets for identical assets (Level 1) | Recurring      
Assets and Liabilities Measured at Fair Value      
Cash equivalents 198,011,000   $ 241,185,000
Significant other observable inputs (Level 2)      
Assets and Liabilities Measured at Fair Value      
Derivative Asset $ 49,019,000    
Minimum      
Level 2 input      
Volatility 21.10%    
Interest rate 1.00%    
Dividend yield 0.00%    
Maximum      
Level 2 input      
Volatility 21.50%    
Interest rate 1.00%    
Dividend yield 0.00%