Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2016

Receivables [Abstract]

Accounts Receivable

	December 31,
	2016			2015
	(in thousands)
Accounts receivable	$	43,091		$	50,139
Less:  Allowance for doubtful accounts	(90		)	(115		)
Total, net	$	43,001		$	50,024

Accounts Receivable (Allowance)

	Years Ending December 31,
	2016			2015			2014
Allowance for doubtful accounts:	(in thousands)
Balance, beginning of period	$	115		$	171		$	193
Provisions for losses on accounts receivables, net of adjustments	(25		)	(48		)	—
Accounts receivable written off, net of recoveries	—			(8		)	(22		)
Balance, end of period	$	90		$	115		$	171