v3.8.0.1
Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Accounting Policies [Abstract]    
Accounts receivable $ 113,450 $ 101,012
Reserve to cover allowances for damages occurring during shipment, quality claims and doubtful accounts 2,100  
Customer trade allowances $ 40,073 $ 40,511