Accounts Receivable

9 Months Ended

Jun. 30, 2013

Receivables [Abstract]

Accounts Receivable

Accounts Receivable

The components of accounts receivable consisted of the following:

	As of			As of
(in thousands)	June 30, 2013			September 30, 2012
Accounts receivable	$	34,683		$	33,893
Accounts receivable – unbilled	7,984			6,325
Accounts receivable, gross	42,667			40,218
Allowance for doubtful accounts	(3,378		)	(3,279		)
Accounts receivable, net	$	39,289		$	36,939

Unbilled accounts receivable represents revenue recognized but not yet billed as of the period ended. Billings on contracts using the percentage-of-completion method usually occur upon completion of predetermined contract milestones or other contract terms, such as customer approval. The allowance for doubtful accounts is based on the age of receivables and a specific identification of receivables considered at risk of collection.

As of June 30, 2013 and September 30, 2012, we had $10.7 million and $6.3 million, respectively, of accounts receivable recorded using the percentage of completion method. Of these amounts, $3.5 million was invoiced and $7.2 million was unbilled as of June 30, 2013 and $1.9 million was invoiced and $4.4 million was unbilled as of September 30, 2012.

Included in accounts receivable, net at June 30, 2013 and September 30, 2012 is $5.6 million and $2.3 million, respectively, from sales to Suncore. See Note 15 - Suncore Joint Venture for additional disclosures related to Suncore.