Annual report pursuant to Section 13 and 15(d)

Goodwill - Summary of Changes to Carrying Amount of Goodwill (Detail)

v3.8.0.1
Goodwill - Summary of Changes to Carrying Amount of Goodwill (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Goodwill [Line Items]    
Beginning, Gross balance $ 42,583 $ 42,097
Beginning, Accumulated impairment losses (17,415) (17,415)
Beginning, Net balance 25,168 24,682
Ending, Gross balance 42,583 42,583
Ending, Accumulated impairment losses (17,415) (17,415)
Ending, Net balance 25,168 25,168
Cappiccille    
Goodwill [Line Items]    
Goodwill, Acquisition $ 0 $ 486