v3.8.0.1
Consolidated Statements of Operations (Parenthetical) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Statement [Abstract]      
Includes non-cash share-based compensation expense $ 4,656 $ 6,279 $ 7,954