Accounts Receivable

12 Months Ended

Oct. 31, 2011

Accounts Receivable [Abstract]

Accounts Receivable

Note 5. Accounts Receivable

Accounts receivable at October 31, 2011 and 2010 consisted of the following:

	2011		2010
U.S. Government:
Amount billed	$	52	$	223
Unbilled recoverable costs		1,012		605
		1,064		828
Commercial customers:
Amount billed	$	10,330	$	9,718
Unbilled recoverable costs		10,556		7,520
		20,886		17,238
	$	21,950	$	18,066

We bill customers for power plant sales based on reaching certain milestones. We bill the U.S. government for research and development contracts based on actual costs incurred, typically in the month subsequent to incurring costs. Unbilled recoverable costs relate to revenue recognized on customer contracts that have not been billed. The amounts above are presented net of an allowance for doubtful accounts of $0.6 million and $0.4 thousand at October 31, 2011 and 2010, respectively.