Valuation and qualifying accounts

12 Months Ended

Dec. 31, 2011

Valuation and qualifying accounts

Valuation and qualifying accounts

17. Valuation and qualifying accounts

        The Company's valuation and qualifying accounts for the years ended December 31, 2011, 2010 and 2009 are as follows:

	Balance at beginning of year		Additions charged to earnings		Changes to reserve, net(1)			Balance at end of year
Year ended December 31, 2011
Allowance for doubtful accounts	$	1,200	$	1,106	$	(1,059	)	$	1,247
Reserves for inventory		1,404		1,080		(1,196	)		1,288
Valuation of deferred tax assets		877		—		(47	)		830
Year ended December 31, 2010
Allowance for doubtful accounts	$	755	$	966	$	(521	)	$	1,200
Reserves for inventory		1,931		930		(1,457	)		1,404
Valuation of deferred tax assets		566		343		(32	)		877
Year ended December 31, 2009
Allowance for doubtful accounts	$	622	$	281	$	(148	)	$	755
Reserves for inventory		1,736		1,347		(1,153	)		1,931
Valuation of deferred tax assets		1,695		84		(1,213	)		566

(1)

Deductions from the allowance for doubtful accounts equal accounts receivable written off, less recoveries, against the allowance. Deductions from the reserves for inventory excess and obsolete items equal inventory written off against the reserve as items were disposed of. Deductions to the valuation of deferred tax assets relate to the reversals due to changes in management's judgments regarding the future realization of the underlying deferred tax assets.