Annual report pursuant to Section 13 and 15(d)

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock Award Plans (Details)

v3.8.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock Award Plans (Details)
12 Months Ended
Dec. 31, 2017
plan
Stock Based Compensation  
Number of stock option plans 4
Purchase plan  
Stock Based Compensation  
Purchase price of common shares as a percentage of the fair market value on the first day of the offering period 85.00%
Purchase price of common shares as a percentage of the fair market value on the purchase date 85.00%