Accounts Receivable, Net and Revenue Concentrations (Tables)

6 Months Ended

Jun. 30, 2018

Receivables [Abstract]

Accounts Receivable, Net and Allowance for Doubtful Accounts

Accounts receivable, net were as follows:

(In thousands)	June 30, 2018			December 31, 2017
Trade receivables, gross	$	140,483		$	142,299
Allowance for doubtful accounts	(1,008		)	(1,064		)
Allowance for sales returns	(596		)	(562		)
Net trade receivables	138,879			140,673
Other	4,783			10,905
Accounts receivable, net	$	143,662		$	151,578

Changes in the allowance for doubtful accounts were as follows:

(In thousands)	Six Months Ended June 30,
	2018			2017
Balance at beginning of period	$	1,064		$	904
Additions to costs and expenses	2			81
(Write-offs)/Foreign exchange effects	(58		)	(35		)
Balance at end of period	$	1,008		$	950

Net Sales to Significant Customers

Net sales to the following customers totaled more than 10% of our net sales:

	Three Months Ended June 30,
	2018				2017
	$ (thousands)		% of Net Sales		$ (thousands)		% of Net Sales
Comcast Corporation	$	29,542	18.2	%	$	42,951	24.2	%
AT&T (1)	$	—	—	%	$	21,740	12.2	%

	Six Months Ended June 30,
	2018				2017
	$ (thousands)		% of Net Sales		$ (thousands)		% of Net Sales
Comcast Corporation	$	67,517	20.6	%	$	85,198	25.1	%
AT&T (1)	$	—	—	%	$	40,940	12.1	%

⁽¹⁾   Sales associated with this customer did not total more than 10% of our net sales for the indicated period.

Trade Receivables Associated with Significant Customers

Trade receivables associated with these significant customers that totaled more than 10% of our accounts receivable, net were as follows:

	June 30, 2018				December 31, 2017
	$ (thousands)		% of Accounts Receivable, Net		$ (thousands)		% of Accounts Receivable, Net
Comcast Corporation	$	19,570	13.6	%	$	25,142	16.6	%