Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at End of Period	$ 2,100		$ 2,600
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period	3,883		2,564		3,409
Charged to Costs and Expenses	1,046		1,784		266
Charged to Other Accounts	0	[1]	1,119	[1]	1,468	[1]
Deductions	1,637	[2]	1,584	[2]	2,579	[2]
Balance at End of Period	3,292		3,883		2,564
Allowance for returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period	2,564		1,361		850
Charged to Costs and Expenses	0		0		0
Charged to Other Accounts	4,473	[3]	10,742	[3]	5,542	[3]
Deductions	4,975	[4]	9,539	[4]	5,031	[4]
Balance at End of Period	2,062		2,564		1,361
Valuation allowance for deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period	18,185		9,235		13,999
Charged to Costs and Expenses	0		0		0
Charged to Other Accounts	8,280	[5]	8,950	[6]	(4,764)	[6]
Deductions	0		0		0
Balance at End of Period	$ 26,465		$ 18,185		$ 9,235

[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.

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