Annual report pursuant to Section 13 and 15(d)

Changes in Carrying Amount of Goodwill (Detail)

v3.7.0.1
Changes in Carrying Amount of Goodwill (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Goodwill [Line Items]    
Goodwill, Beginning Balance $ 64,267 $ 43,000
Acquisitions [1] 7,800 21,300
Goodwill, Ending Balance $ 72,074 $ 64,267
[1] Reflects the effects of the TNT acquisition during 2016 ($7.8 million) and the Energy Source acquisition during 2015 ($21.3 million). See Note 3.