Accounts Receivable and Sales Concentrations

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Accounts Receivable and Sales Concentrations

Accounts Receivable and Sales Concentrations

Accounts receivable, net are comprised of the following amounts:

	As of December 31,
	2018		2017
Trade	$	135,260	$	110,165
Less—allowance for doubtful accounts	1,839		1,719
Accounts receivable, net	$	133,421	$	108,446

The following table presents activity in the allowance for doubtful accounts.

	Year Ended December 31,
	2018			2017			2016
Balance at beginning of year	$	1,719		$	1,069		$	1,055
Additions	754			648			153
Write-offs	(584		)	(101		)	(59		)
Currency impact	(50		)	103			(80		)
Balance at end of year	$	1,839		$	1,719		$	1,069

No customers accounted for more than 10% of our net sales for the years ended December 31, 2018 and 2017. For the year ended December 31, 2016, sales to Robert Bosch Automotive Systems (“Bosch”) amounted to $59.2 million or 10% of consolidated net sales. All revenues related to Bosch are reported in Mobile Solutions. No customers represented more than 10% of accounts receivable as of December 31, 2018 or 2017.