Related Parties (Tables)

12 Months Ended

Dec. 31, 2017

Related Party Transactions [Abstract]

Schedule of Related Party Transactions

Following is a summary of transactions and balance with affiliates:

	Years Ending December 31,
	2017		2016		2015
	(in thousands)
Sales to affiliates	$	1,579	$	1,671	$	1,532
Payments to affiliates	432		697		841
			December 31,
			2017		2016
			(in thousands)
Due from affiliates			$	9	$	10
Due to affiliates			—		—