Accounts Receivable, Net

12 Months Ended

Dec. 31, 2017

Accounts Receivable Net [Abstract]

Accounts Receivable, Net

(3) Accounts Receivable, Net

Accounts receivable, net, is as follows (in thousands):

	As of December 31,
	2017			2016
Accounts receivable	$	32,662		$	18,231
Allowance for doubtful accounts and sales return reserve		(963	)		(419	)
Net accounts receivable	$	31,699		$	17,812

Bad debt expense for the years ended December 31, 2017, 2016 and 2015 was $0.6 million, $0.4 million and $0.2 million, respectively.

The following table summarizes the changes in the allowance for doubtful accounts (in thousands):

	As of December 31,
	2017			2016
Allowance, at beginning of period	$	(374	)	$	(381	)
Charged to bad debt expense		(558	)		(387	)
Write-offs, net of recoveries		69			394
Allowance, at end of period	$	(863	)	$	(374	)

The following table summarizes the changes in the sales reserve (in thousands):

	As of December 31,
	2017			2016
Balance, beginning of period	$	(45	)	$	(45	)
Additions		(79	)		—
Write-offs		24			—
Balance, end of period	$	(100	)	$	(45	)