Receivables (Tables)

12 Months Ended

Sep. 30, 2015

Receivables [Abstract]

Receivables

Receivables at September 30, 2015 and 2014 consisted of the following:

	September 30,
	2015			2014
	(In thousands)
Billed	$	114,464		$	123,083
Unbilled (1)	46,435			35,139
	160,899			158,222
Less: allowance for doubtful accounts	(2,126		)	(2,927		)
Receivables, net	$	158,773		$	155,295

(1) Represents revenue recorded in excess of amounts billable pursuant to contract provisions and generally become billable at contractually specified dates or upon the attainment of milestones. Unbilled amounts are expected to be realized within one year.

Activity of Allowance for Doubtful Accounts

Activity in the allowance for doubtful accounts was as follows:

	Year Ended September 30,
	2015			2014
	(In thousands)
Balance, beginning of year	$	2,927		$	3,157
Add: expense	—			1,485
Less: write-offs (net of recoveries)	(801		)	(1,715		)
Balance, end of year	$	2,126		$	2,927