Accounts Receivable

3 Months Ended

Dec. 31, 2013

Receivables [Abstract]

Accounts Receivable

Accounts Receivable

The components of accounts receivable consisted of the following:

	As of			As of
(in thousands)	December 31, 2013			September 30, 2013
Accounts receivable	$	31,998		$	39,827
Accounts receivable – unbilled	4,356			5,362
Accounts receivable, gross	36,354			45,189
Allowance for doubtful accounts	(434		)	(3,363		)
Accounts receivable, net	$	35,920		$	41,826

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 December 31, 2013 and September 30, 2013, we had $5.5 million and $9.2 million, respectively, of accounts receivable recorded using the percentage of completion method. Of these amounts, $1.7 million was invoiced and $3.8 million was unbilled as of December 31, 2013 and $4.6 million was invoiced and $4.6 million was unbilled as of September 30, 2013.

Included in accounts receivable, net at December 31, 2013 and September 30, 2013 is $0.9 million and $6.5 million, respectively, from sales to Suncore. See Note 15 - Suncore Joint Venture for additional disclosures related to Suncore.

The decrease in the allowance for doubtful accounts during the three months ended December 31, 2013 is primarily due to historical amounts that were written off.