Activity in our allowance for doubtful accounts on accounts and long-term receivables consists of the following:

	Years Ended September 30,
	2012		2011
Balance at beginning of period	$	2,704	$	7,429
Additions to costs and expenses		771		1,071
Deductions for uncollectible receivables written off, net of recoveries		(1,687)		(5,796)
Balance at end of period	$	1,788	$	2,704

	Years Ended September 30,
	2012		2011
Accounts payable, trade	$	39,879	$	49,556
Accrued compensation and benefits		13,312		11,662
Accrued insurance liabilities		5,229		7,040
Other accrued expenses		10,253		10,722
	$	68,673	$	78,980

	Years Ended September 30,
	2012		2011
Costs incurred on contracts in progress	$	402,738	$	335,204
Estimated earnings		33,931		21,942
		436,669		357,146
Less--Billings to date		(453,744)		(366,768)
Net contracts in progress	$	(17,075)	$	(9,622)
Costs and estimated earnings in excess of billings on uncompleted contracts		8,180		9,963
Less--Billings in excess of costs and estimated earnings on uncompleted contracts		(25,255)		(19,585)
Net contracts in progress	$	(17,075)	$	(9,622)

	Years Ended September 30,
	2012		2011
Deposits	$	2,137	$	3,986
Deferred tax assets		1,065		1,040
Executive Savings Plan assets		533		477
Securities and equity investments		919		1,003
Other		1,489		581
Total	$	6,143	$	7,087

We assessed the fair market value of our investment in EPV after its restructuring in 2009 and determined that it was below its carrying value. Accordingly, we recorded a $2,850 other-than-temporary impairment loss for the year ended September 30, 2009. The total impairment loss is reflected in our Consolidated Statements of Operations as a component of Other Expense and reduced the carrying value of our investment from $3,000 to $150 at September 30, 2009.

On February 24, 2010, EPV filed for Chapter 11 bankruptcy protection. On August 20, 2010, the United States Bankruptcy Court District of New Jersey authorized and approved the sale of substantially all of EPV's assets free and clear of liens, claims, encumbrances and interests to a third-party solar company. As this sale cancelled our claims to our convertible note receivable, we recorded an impairment loss of $150 during the year ended September 30, 2010, which reduced its carrying value to $0.

In April 2000, we committed to invest up to $5,000 in EnerTech. As of September 30, 2009, we fulfilled our $5,000 investment under this commitment. As our investment is 2.31% of the overall ownership in EnerTech at September 30, 2012 and 2011, we account for this investment using the cost method of accounting. EnerTech's investment portfolio from time to time results in unrealized losses reflecting a possible, other-than-temporary, impairment of our investment. The carrying value of our investment in EnerTech at September 30, 2012 and 2011 was $919 and $1,003, respectively. Our results of operations for the year ended September 30, 2011, includes a write down of $967 attributable to our investment in EnerTech.

The following table presents the reconciliation of the carrying value and unrealized gains (losses) to the fair value of the investment in EnerTech as of September 30, 2012 and 2011:

	Years Ended September 30,
	2012		2011
Carrying value	$	919	$	1,003
Unrealized gains		69		-
Fair value	$	988	$	1,003

At each reporting date, the Company performs evaluations of impairment for securities to determine if any unrealized losses are other-than-temporary. For equity securities, this evaluation considers a number of factors including, but not limited to, the length of time and extent to which the fair value has been less than cost, the financial condition and near term prospects of the issuer and management's ability and intent to hold the securities until fair value recovers. The assessment of the ability and intent to hold these securities to recovery focuses on liquidity needs, asset and liability management objectives and securities portfolio objectives. Based on the results of this evaluation, we believe the unrealized gain at September 30, 2012 indicated our investment was not impaired. As of September 30, 2012 and 2011, the carrying value of these investments was $919 and $1,003, respectively. See Note 15, “Fair Value Measurements” for related disclosures relative to fair value measurements.

In June 2012, we received a distribution from Enertech of $84, which was applied as a reduction in the carrying value of the investment.

On December 31, 2011, EnerTech's general partner, with the consent of the fund's investors, extended the fund through December 31, 2012. The fund will terminate on this date unless extended by the fund's valuation committee. The fund may be extended for another one-year period through December 31, 2013 with the consent of the fund's valuation committee.