Accounts Receivable (Tables)

9 Months Ended

Sep. 30, 2015

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

Schedule of Accounts Receivable

Net accounts receivable consisted of the following as of September 30, 2015 and December 31, 2014 (in thousands):

	September 30, 2015			December 31, 2014
Trade accounts receivable	$	251,911		$	222,531
Unbilled accounts receivable	123,053			116,070
Gross accounts receivable	374,964			338,601
Allowance for doubtful accounts	(641		)	(1,033		)
Reserve for cash-basis customers	(8,366		)	(7,990		)
Total accounts receivable reserves	(9,007		)	(9,023		)
Accounts receivable, net	$	365,957		$	329,578