Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for doubtful accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 3,040	$ 2,827	$ 2,921
Additions	0	600	0
Deductions	(17)	(387)	(94)
Balance at End of Year	3,023	3,040	2,827
Sales returns and allowances
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	37,350	34,654	37,422
Additions	135,395	86,649	93,101
Deductions	(124,378)	(83,953)	(95,869)
Balance at End of Year	48,367	37,350	34,654
Income tax valuation allowance
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	3,216	3,359	3,161
Additions	8,620	0	460
Deductions	(461)	(143)	(262)
Balance at End of Year	$ 11,375	$ 3,216	$ 3,359