Nature of Operations, Accounting Policies of Consolidated Financial Statements - Additional Information (Detail) - USD ($)	12 Months Ended
	May 31, 2016	May 31, 2015
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts	$ 0	$ 536,000
Impairment of long-lived assets	$ 0
Stock options granted	225,000
Interest paid	$ 237,000	$ 339,000
2015 Stock Incentive Plan [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Stock options granted	225,000
Home Sales [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Product warranty	15 months
Building and Improvements [Member] | Minimum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of property, plant and equipment	10 years
Building and Improvements [Member] | Maximum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of property, plant and equipment	30 years
Machinery and Equipment [Member] | Minimum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of property, plant and equipment	5 years
Machinery and Equipment [Member] | Maximum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of property, plant and equipment	8 years