4. Receivables

Receivables consisted of the following (dollars in thousands):

	December 31,
	2014			2013
Customers and other	$	36,417		$	38,463
Allowance for doubtful accounts		(3,755	)		(3,942	)

	$	32,662		$	34,521

The Company grants credit to customers in the normal course of business. At December 31, 2014 and 2013, the Company did not have customer balances representing more than 10% of total receivables. During the years ended December 31, 2014, 2013 and 2012, the Company had no customers that represented more than 10% of total revenues.

The following is a summary of activity for the allowance for doubtful accounts (dollars in thousands):

	Beginning Balance		Additional Charges to Costs and Expenses		Deductions from Allowance			Ending Balance
January 1 to December 31, 2014	$	3,942	$	3,590	$	(3,777	)	$	3,755
January 1 to December 31, 2013		2,631		3,455		(2,144	)		3,942
January 1 to December 31, 2012		2,924		716		(1,009	)		2,631

In the summary above, the additional charges to costs and expenses for the year ended December 31, 2012 is net of a $4.0 million settlement gain relating to the preexisting relationship with Wavecom.