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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Revenue Recognition - Additional Information (Detail)	3 Months Ended		6 Months Ended
Revenue Recognition - Additional Information (Detail)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Segment	Jun. 30, 2017 USD ($)	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)
Disaggregation Of Revenue [Line Items]
Number of reportable segment \| Segment			1
Cost of sales	$ 1,081,016,000	$ 1,100,000,000	$ 2,199,996,000	$ 2,200,000,000
Revenue remaining performance obligations	$ 0		$ 0			$ 0
Description of payment terms			Payment terms for net merchandise sales, fulfillment and other services are dependent on the agreed upon contractual repayment terms of the customer. Typically, these vary dependent on the size of the customer and its risk profile to the Company. Some customers receive discounts based on the contractual terms wherein early payment reduces the net payment amount. Conversely, for some customers the Company provides enhanced payment terms which can extend up to and in excess of one year from invoicing.
United States [Member] \| Geographic Concentration Risk [Member] \| Net sales [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregates revenue on net sales	98.00%	98.00%	98.00%	98.00%
Topic 606 [Member]
Disaggregation Of Revenue [Line Items]
Net reduction to beginning retained earnings due to cumulative impact					$ 400,000