Annual report pursuant to Section 13 and 15(d)

Changes in Carrying Amount of Goodwill (Parenthetical) (Detail)

v3.7.0.1
Changes in Carrying Amount of Goodwill (Parenthetical) (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Goodwill [Line Items]    
Business acquisition [1] $ 7.8 $ 21.3
TNT    
Goodwill [Line Items]    
Business acquisition $ 7.8  
Energy Source    
Goodwill [Line Items]    
Business acquisition   $ 21.3
[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.