Accounts Receivable, Net

9 Months Ended

Sep. 30, 2011

Accounts Receivable, Net [Abstract]

Accounts Receivable, Net

2. Accounts Receivable, Net

Accounts receivable balances at September 30, 2011 and December 31, 2010 were as follows (in thousands):

	2011			2010
Trade accounts receivable	$	119,533		$	119,205
Unbilled revenue		48,563			29,483
Total accounts receivable		168,096			148,688
Allowance for doubtful accounts		(9,784	)		(10,620	)
Accounts receivable, net	$	158,312		$	138,068