Receivables

12 Months Ended

Dec. 31, 2011

Receivables [Abstract]

Receivables

4. Receivables

Accounts receivable – trade, net consisted of the following:

	December 31,
	2011			2010
Accounts receivable—trade	$	239,033		$	172,857
Allowance for doubtful accounts		(1,044	)		(1,307	)
Accounts receivable—trade, net	$	237,989		$	171,550

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

	December 31,
	2011			2010			2009
Balance at beginning of period	$	1,307		$	1,372		$	1,132
Charged to costs and expenses		373			491			558
Amounts written off		(636	)		(556	)		(320	)
Recoveries		—			—			2
Balance at end of period	$	1,044		$	1,307		$	1,372