D. Detail of Selected Balance Sheet Accounts

Allowance for Doubtful Accounts

Activity in our allowance for doubtful accounts consisted of the following (in thousands):


	September 30,
	2014			2013
Balance at beginning of period	$	572		$	1,297
Bad debt expense/(recovery)		1,074			(544	)
Uncollectible accounts written off, net of recoveries		(58	)		(171	)
Change in foreign currency translation		(11	)		(10	)
Balance at end of period	$	1,577		$	572

Inventories

The components of inventories are summarized below (in thousands):

	September 30,
	2014			2013
Raw materials, parts and subassemblies	$	35,349		$	30,077
Work-in-progress		2,035			3,818
Provision for excess and obsolete inventory		(4,569	)		(4,932	)
Total inventories	$	32,815		$	28,963

Cost and Estimated Earnings on Uncompleted Contracts

The components of costs and estimated earnings and related amounts billed on uncompleted contracts are summarized below (in thousands):

	September 30,
	2014			2013
Costs incurred on uncompleted contracts	$	604,939		$	618,570
Estimated earnings		157,562			159,962
		762,501			778,532
Less: Billings to date		(715,233	)		(747,446	)
Net underbilled position	$	47,268		$	31,086

Included in the accompanying balance sheets under the following captions:
Costs and estimated earnings in excess of billings on uncompleted contracts – underbilled	$	95,970		$	79,420
Billings in excess of costs and estimated earnings on uncompleted contracts – overbilled		(48,702	)		(48,334	)
Net underbilled position	$	47,268		$	31,086

Property, Plant and Equipment

Property, plant and equipment are summarized below (in thousands):

	September 30,						Range of
	2014			2013			Asset Lives
Land	$	23,545		$	24,022		—
Buildings and improvements		100,901			79,621		3 - 39 Years
Machinery and equipment		100,922			71,808		3 - 15 Years
Furniture and fixtures		3,852			2,736		3 - 10 Years
Construction in process		15,878			48,301		—
	$	245,098		$	226,488
Less: Accumulated depreciation		(88,202	)		(81,993	)
Total property, plant and equipment, net	$	156,896		$	144,495

The increase in buildings and improvements and machinery and equipment was primarily the result of construction of the new facilities in Houston, Texas, and Acheson, Alberta, Canada.

There were no assets under capital lease as of September 30, 2014; however, at September 30, 2013, we had assets under capital lease of $0.5 million, with related accumulated depreciation of $0.5 million which was included in property and equipment. Depreciation expense from continuing operations, including the depreciation of capital leases, was $11.4 million, $8.5 million and $10.5 million for fiscal years 2014, 2013 and 2012, respectively.

Warranty Accrual

Activity in our product warranty accrual consisted of the following (in thousands):

	September 30,
	2014			2013
Balance at beginning of period	$	5,282		$	5,548
Increase to warranty expense		3,237			4,020
Deduction for warranty charges		(3,892	)		(4,321	)
Increase (decrease) due to foreign currency translations		(70	)		35
Balance at end of period	$	4,557		$	5,282