Accounts Receivable (Tables)

9 Months Ended

Sep. 30, 2017

Receivables [Abstract]

Accounts Receivable

	September 30, 2017			December 31, 2016
	(in thousands)
Accounts receivable	$	57,462		$	43,091
Less:  Allowance for doubtful accounts	(120		)	(90		)
Total, net	$	57,342		$	43,001

Allowance for Doubtful Accounts

	Three months ended				Nine months ended
	September 30, 2017		September 30, 2016		September 30, 2017			September 30, 2016
Allowance for doubtful accounts:	(in thousands)
Balance, beginning of period	$	81	$	73	$	90		$	115
Provisions for losses on accounts receivables, net of recoveries	39		72		180			30
Accounts receivable written off	—		—		(150		)	—
Balance, end of period	$	120	$	145	$	120		$	145