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[Line Items] for Significant Accounting Policies [Table]

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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of the cumulative effect on retained earnings before related income tax effect.

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The total expense recognized in the period for promotion, public relations, and brand or product advertising.

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Amount of consideration paid in advance for advertising that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

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Significant Accounting Policies (Details)		12 Months Ended
Significant Accounting Policies (Details)	Jan. 01, 2017 USD ($)	Dec. 31, 2017 USD ($) customer	Dec. 31, 2016 USD ($) customer	Dec. 31, 2015 USD ($) customer
Significant Accounting Policies [Line Items]
Asset impairment charge		$ 8,800,000	$ 0	$ 0
Movement in Valuation Allowances and Reserves [Roll Forward]
Marketing and advertising expense		66,400,000	60,700,000	$ 54,800,000
Prepaid advertising		$ 1,500,000	$ 3,500,000
Minimum
Significant Accounting Policies [Line Items]
Product Warranty Period		30 days
Furniture, equipment and information systems [Member] \| Minimum
Significant Accounting Policies [Line Items]
Estimated useful life (in years)		3 years
Furniture, equipment and information systems [Member] \| Maximum
Significant Accounting Policies [Line Items]
Estimated useful life (in years)		7 years
Customer Concentration Risk \| Consolidated Net Sales
Significant Accounting Policies [Line Items]
Number of major customers \| customer		1	1,000	1,000
Customer Concentration Risk \| Customer A [Member] \| Consolidated Net Sales \| Minimum
Significant Accounting Policies [Line Items]
Concentration risk, percentage		10.00%	10.00%	10.00%
Customer Concentration Risk \| Customer A [Member] \| Consolidated Net Sales \| Maximum
Significant Accounting Policies [Line Items]
Concentration risk, percentage		15.00%	15.00%	15.00%
Sales Discounts and Returns Allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	$ 5,901,000	$ 5,901,000	$ 5,677,000	$ 4,296,000
Charges to reserve		18,377,000	12,935,000	16,700,000
Reductions for sales discounts and returns		(17,358,000)	(12,711,000)	(15,569,000)
Business acquisition (Note 2)		0	0	250,000
Ending Balance		6,920,000	5,901,000	$ 5,677,000
Fair Value, Measurements, Recurring
Significant Accounting Policies [Line Items]
Cash Equivalents		$ 12,942,000	$ 13,634,000
Accounting Standards Update 2016-09
Movement in Valuation Allowances and Reserves [Roll Forward]
Cumulative effect on retained earnings	$ 28,308