Accounts Receivable, net (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Receivables [Abstract]
Accounts receivable, gross	$ 41,742		$ 45,041
Less allowance for doubtful accounts	(1,334)		(1,237)
Total accounts receivable, net	$ 40,408	$ 47,521	$ 43,804