Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Share-Based Payment (Schedule of Weighted Average Fair Values and Exercise Price) (Details)

v3.19.1
Share-Based Payment (Schedule of Weighted Average Fair Values and Exercise Price) (Details) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure of terms and conditions of share-based payment arrangement [abstract]      
Weighted average exercise prices $ 8.95 $ 9.02 $ 8.3
Weighted average fair value on grant date $ 2.1 $ 1.8