Accounts Receivable

12 Months Ended

Dec. 31, 2012

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

Accounts Receivable

Accounts Receivable:

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

	December 31,
	2012			2011
Trade accounts receivable	$	143,533		$	142,166
Unbilled accounts	79,051			73,325
Gross accounts receivable	222,584			215,491
Allowance for doubtful accounts	(1,154		)	(1,627		)
Reserve for cash-basis customers	(2,653		)	(2,928		)
Total accounts receivable reserves	(3,807		)	(4,555		)
Accounts receivable, net	$	218,777		$	210,936