Annual report pursuant to Section 13 and 15(d)

Accounts Receivable, Net of Allowance for Doubtful Accounts - Additional Information (Detail)

v3.8.0.1
Accounts Receivable, Net of Allowance for Doubtful Accounts - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Other selling, general and administrative      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Bad debt expense $ 0.5 $ 1.5 $ 1.3