Commitments and Contingencies (Detail)		1 Months Ended	9 Months Ended	12 Months Ended	21 Months Ended
	Oct. 21, 2016 USD ($) authority	Sep. 30, 2016 USD ($) a	Sep. 30, 2016 USD ($) a	Dec. 31, 2015 USD ($)	Sep. 30, 2016 USD ($) a
Long-term Purchase Commitment [Line Items]
Commitments			$ 56,848,000
Capital Expenditures [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase commitments		$ 4,197,000	$ 4,197,000		$ 4,197,000
Warehouse Expansion [Member]
Long-term Purchase Commitment [Line Items]
Commitments		$ 8,800,000		$ 20,200,000	$ 29,000,000
Area of campus (in acres) | a		20	20		20
Strategic growth period			5 years
Purchases made against approved investment amount			$ 17,676,000
Subsequent Event [Member]
Long-term Purchase Commitment [Line Items]
Number of regulatory authorities that may impose penalty or fine, | authority	1
Insurance deductible	$ 250,000