Accounts Receivable, Net

3 Months Ended

Mar. 31, 2013

Accounts Receivable, Net [Abstract]

Accounts Receivable, Net

2. Accounts Receivable, Net

Accounts receivable balances at March 31, 2013 and December 31, 2012 were as follows (in thousands):

	March 31, 2013			December 31, 2012
Trade accounts receivable	$	137,405		$	125,787
Unbilled revenue		67,966			41,005
Total accounts receivable		205,371			166,792
Allowance for doubtful accounts		(12,153	)		(11,819	)
Accounts receivable, net	$	193,218		$	154,973