Summary of Significant Accounting Policies (Tables)
6 Months Ended
Jun. 30, 2018
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract]  
Reconciliation of cash, cash equivalents and restricted cash

  

  

 

June 30,

2018

 

  

December 31,

2017

 

Reconciliation of cash, cash equivalents and restricted cash:

  

 

 

 

  

 

 

 

Current assets:

  

 

 

 

  

 

 

 

Cash and cash equivalents

 

 

118,454

 

 

 

127,632

 

Restricted cash

  

 

2,978

 

  

 

6,558

 

Total cash and cash equivalents and restricted cash

  

$

121,432

 

  

$

134,190