Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Allowance for Doubtful Accounts [Member]
Beginning of Period	$ 3,409		$ 3,219		$ 7,061
Charged to Costs and Expenses	266		2,035		1,734
Charged to Other Accounts	1,468	[1]	0	[1]	(422)	[1]
Deductions	2,579	[2]	1,845	[2]	5,154	[2]
Balance at End of Period	2,564		3,409		3,219
Allowance for Returns [Member]
Beginning of Period	850		1,617		1,641
Charged to Costs and Expenses	0		0		0
Charged to Other Accounts	5,542	[3]	2,427	[3]	3,332	[3]
Deductions	5,031	[4]	3,194	[4]	3,356	[4]
Balance at End of Period	1,361		850		1,617
Valuation Allowance for Deferred Tax Assets [Member]
Beginning of Period	13,999		8,680		14,217
Charged to Costs and Expenses	0		0		0
Charged to Other Accounts	(4,764)	[5]	5,319	[6]	(5,537)	[6]
Deductions	0		0		0
Balance at End of Period	$ 9,235		$ 13,999		$ 8,680

[1] Adjustments from acquisitions.

[2] Uncollectible accounts written off, net of recoveries.

[3] Charged against revenues.

[4] Credits issued for returns.

[5] Related to deferred tax assets on foreign tax credits, net operating loss carryforwards, and depreciation in foreign jurisdictions.

[6] Related to deferred tax assets on unrealized losses and acquisitions.