Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Comprehensive Income (Parenthetical)

v3.8.0.1
Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Statement [Abstract]      
Depreciation $ 9,835 $ 11,429 $ 11,965