Accounts Receivable (Tables)

9 Months Ended

Sep. 30, 2011

Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]

Schedule of Accounts Receivable

Net accounts receivable consisted of the following (in thousands):

	September 30, 2011			December 31, 2010
Trade accounts receivable	$	127,210		$	116,212
Unbilled accounts	61,131			64,386
Gross accounts receivable	188,341			180,598
Allowance for doubtful accounts	(2,127		)	(1,329		)
Reserve for cash-basis customers	(3,549		)	(3,903		)
Total accounts receivable reserves	(5,676		)	(5,232		)
Accounts receivable, net	$	182,665		$	175,366