Schedule II Valuation and Qualifying Accounts (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Valuation and Qualifying Accounts [Roll Forward]
Balance at beginning of year	$ 6,369,000		$ 6,969,000	$ 6,124,000
Charged to costs and expenses	13,243,000		13,071,000	15,443,000
Other	0		0	0
Deductions	15,366,000		13,671,000	14,598,000
Balance at end of year	4,246,000		6,369,000	6,969,000
Allowance for doubtful accounts receivable, pre-tax charge	3,514,000
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts [Roll Forward]
Balance at beginning of year	4,894,000		5,528,000	4,944,000
Charged to costs and expenses	3,371,000	[1]	(497,000)	641,000
Other	0		0	0
Deductions	5,064,000		137,000	57,000
Balance at end of year	3,201,000		4,894,000	5,528,000
Allowance for Discounts [Member]
Valuation and Qualifying Accounts [Roll Forward]
Balance at beginning of year	1,475,000		1,441,000	1,180,000
Charged to costs and expenses	9,872,000		13,568,000	14,802,000
Other	0		0	0
Deductions	10,302,000		13,534,000	14,541,000
Balance at end of year	1,045,000		1,475,000	1,441,000
Allowance for Sales Returns [Member]
Valuation and Qualifying Accounts [Roll Forward]
Balance at beginning of year	30,621,000		31,464,000	29,033,000
Charged to costs and expenses	133,355,000		126,608,000	114,958,000
Other	0		0	0
Deductions	125,164,000		127,451,000	112,527,000
Balance at end of year	$ 38,812,000		$ 30,621,000	$ 31,464,000

[1] Includes a net $3,514,000 charge relating to one of our customers that filed a petition for bankruptcy in January 2016.