Accounts Receivable, Net

6 Months Ended

Jun. 30, 2011

Accounts Receivable, Net [Abstract]

Accounts Receivable, Net

2. Accounts Receivable, Net

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

	2011			2010
Trade accounts receivable	$	125,042		$	119,205
Unbilled revenue		40,984			29,483
Total accounts receivable		166,026			148,688
Allowance for doubtful accounts		(10,363	)		(10,620	)
Accounts receivable, net	$	155,663		$	138,068