Description	Balance at Beginning of Period		Charges to Earnings			Charges to Other Accounts			Deductions			Balance at End of Period

	(In thousands)
2011
Allowance for doubtful accounts and revenue reserves	$	8,848	$	8,898	⁽¹⁾	$	(329	)	$	(10,108	)⁽⁴⁾	$	7,309
Sales returns accrual		913		107			—			—			1,020
Deferred tax valuation allowance		40,266		5,732	⁽²⁾		(914	)⁽³⁾		—			45,084
Other reserves		1,555											2,119
2010
Allowance for doubtful accounts and revenue reserves	$	10,515	$	9,013	⁽¹⁾	$	81		$	(10,761	)⁽⁴⁾	$	8,848
Sales returns accrual		873		40			—			—			913
Deferred tax valuation allowance		35,331		4,511	⁽⁵⁾		424	⁽⁶⁾		—			40,266
Other reserves		2,666											1,555
2009
Allowance for doubtful accounts and revenue reserves	$	10,293	$	10,361	⁽¹⁾	$	(520	)	$	(9,619	)⁽⁴⁾	$	10,515
Sales returns accrual		794		79			—			—			873
Deferred tax valuation allowance		39,515		(1,728	)⁽⁷⁾		(2,456	)⁽⁸⁾		—			35,331
Other reserves		3,079											2,666

(1): Additions to the allowance for doubtful accounts is charged to expense. Additions to the revenue reserve is charged against revenue.
(2): Amount is primarily related to losses from equity method investments.
(3): Amount is primary related to the net release of the valuation allowance on net benefited losses for 2011 unrealized gains on available-for-sale securities included in accumulated other comprehensive income.
(4): Write-off of fully reserved accounts receivable.
(5): Amount is primarily related to net unbenefited unrealized losses including an impairment charge from equity method investments and an increase in foreign net operating losses partially offset by a write-off of previously unbenefited deferred tax assets for state capital loss carryforwards.
(6): Amount is primary related to unbenefited unrealized losses on available-for-sale securities included in accumulated other comprehensive income.
(7): Amount is primarily related to a decrease in state net operating losses partially offset by an increase for unbenefited state capital loss carryforwards and foreign net operating losses.
(8): Amount is primarily related to the release of a valuation allowance on net benefited losses for 2009 unrealized gains on available-for-sale securities included in accumulated other comprehensive income.