Receivables

12 Months Ended

Dec. 31, 2012

Accounts Receivable, Net, Current [Abstract]

Receivables

4. Receivables

Accounts receivable – trade, net consisted of the following:

	December 31,
	2012			2011
Accounts receivable - trade	$	273,297		$	239,033
Allowance for doubtful accounts	(2,372		)	(1,044		)
Accounts receivable - trade, net	$	270,925		$	237,989

The following table presents the activity of our allowance for doubtful accounts for the periods indicated:

	December 31,
	2012			2011			2010
Balance at beginning of period	$	1,044		$	1,307		$	1,372
Charged to costs and expenses	2,096			373			491
Amounts written off	(768		)	(636		)	(556		)
Balance at end of period	$	2,372		$	1,044		$	1,307