Quarterly report pursuant to Section 13 or 15(d)

Accounts Receivable and Allowance for Doubtful Accounts (Details)

v3.10.0.1
Accounts Receivable and Allowance for Doubtful Accounts (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accounts receivable $ 112,448 $ 103,506
Retainage 28,160 26,070
Allowance for doubtful accounts (279) (233)
Accounts receivable, net $ 140,329 $ 129,343