Commitments and Contingencies (Detail)			1 Months Ended	3 Months Ended	12 Months Ended	21 Months Ended
	Apr. 19, 2017 USD ($)	Oct. 21, 2016 USD ($)	Sep. 30, 2016 USD ($)	Mar. 31, 2017 USD ($) a	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)
Long-term Purchase Commitment [Line Items]
Commitments				$ 68,090,000
Insurance deductible		$ 250,000
Capital Expenditures [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase commitments				$ 2,523,000
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
Strategic growth period				5 years
Purchases made against approved investment amount				$ 22,231,000
Subsequent Event [Member]
Long-term Purchase Commitment [Line Items]
Penalty issued by OSHA	$ 138,000