Detail of Certain Balance Sheet Accounts (Tables)

12 Months Ended

Dec. 31, 2012

Detail of Certain Balance Sheet Accounts

Schedule of activity in allowance for doubtful accounts

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

	December 31,
	2012			2011			2010
Balance at beginning of year	$	4,615		$	5,029		$	7,200
Additions for bad debt expense		2,753			214			340
Deductions for uncollectible receivables written off, net of recoveries		(1,090	)		(770	)		(2,689	)
Allowance for doubtful accounts of acquired companies at date of acquisition		55			142			178
Balance at end of year	$	6,333		$	4,615		$	5,029

Schedule of other current liabilities

Other current liabilities consist of the following (in thousands):

	December 31,
	2012		2011
Accrued warranty costs	$	6,781	$	8,234
Accrued job losses		2,137		1,777
Accrued rent and lease obligations		673		2,793
Accrued sales and use tax		1,710		1,494
Deferred revenue		1,143		1,592
Liabilities due to former owners		2,349		—
Other current liabilities		12,284		13,959
	$	27,077	$	29,849

Schedule of contracts in progress

Contracts in progress are as follows (in thousands):

	December 31,
	2012			2011
Costs incurred on contracts in progress	$	1,182,085		$	1,071,406
Estimated earnings, net of losses		134,534			132,096
Less—Billings to date		(1,364,229	)		(1,247,535	)
	$	(47,610	)	$	(44,033	)
Costs and estimated earnings in excess of billings	$	26,204		$	26,602
Billings in excess of costs and estimated earnings		(73,814	)		(70,635	)
	$	(47,610	)	$	(44,033	)