Significant Accounting Policies - Estimated Life of Property and Equipment (Detail)	12 Months Ended
	Sep. 30, 2017
Buildings and Improvements [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	5 years
Buildings and Improvements [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	40 years
Machinery and Equipment [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	3 years
Machinery and Equipment [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	10 years
Furniture and Fixtures [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	10 years
Vehicles [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	3 years
Vehicles [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Property and equipment useful life	5 years