Schedule II Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred tax valuation allowance
Valuation and Qualifying Accounts
Balance at Beginning of Year	$ 83,617	$ 77,051	$ 80,245
Charged to Expense		6,566
Deductions	3,924		3,194
Balance at End of Year	79,693	83,617	77,051
Allowance for sales returns
Valuation and Qualifying Accounts
Balance at Beginning of Year	10,899	11,525	11,923
Charged to Expense	79,785	83,129	88,473
Deductions	80,066	83,755	88,871
Balance at End of Year	10,618	10,899	11,525
Allowance for doubtful accounts
Valuation and Qualifying Accounts
Balance at Beginning of Year	574	2,048	1,730
Charged to Expense	249	268	780
Deductions	26	1,742	462
Balance at End of Year	$ 797	$ 574	$ 2,048