Annual report pursuant to Section 13 and 15(d)

GOODWILL (Details)

v3.8.0.1
GOODWILL (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]    
Carrying amount of goodwill in foreign countries $ 46,300 $ 42,700
Changes in the carrying amount of goodwill    
Goodwill balance at the beginning of the period 255,665 249,939
Goodwill acquired 87,261 8,613
Goodwill adjustments due to currency translation 3,588 (2,887)
Goodwill balance at the end of the period $ 346,514 $ 255,665