Annual report pursuant to Section 13 and 15(d)

Changes in Carrying Amount of Goodwill (Detail)

v3.3.1.900
Changes in Carrying Amount of Goodwill (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2015
Goodwill [Line Items]      
Goodwill, Beginning Balance $ 42,991 $ 21,498  
Business acquisition 21,276 21,493  
Goodwill, Ending Balance 64,267 42,991  
Goodwill, Gross     $ 66,663
Accumulated impairment losses     (2,396)
Goodwill $ 42,991 $ 21,498 $ 64,267