SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS

12 Months Ended

Dec. 31, 2017

Valuation and Qualifying Accounts [Abstract]

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS

SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS

	Years Ended December 31,
	2017			2016			2015
				(in thousands)
Allowance for bad debts:
Beginning balance	$	643		$	605		$	490
Additions		346			344			379
Write-offs		(311	)		(306	)		(264	)
Ending balance	$	678		$	643		$	605
Allowance for customer credits:
Beginning balance	$	371		$	439		$	280
Additions		247			592			803
Write-offs		(405	)		(660	)		(644	)
Ending balance	$	213		$	371		$	439
Tax valuation allowance:
Beginning balance	$	4,656		$	5,427		$	6,015
Charged (credited) to tax expense		21,247			(771	)		(588	)
Charged (credited) to retained earnings		(4,585	)		—			—
Ending balance	$	21,318		$	4,656		$	5,427