Notes Receivable (Details) - USD ($)	1 Months Ended	3 Months Ended
	Apr. 30, 2014	Jun. 30, 2016	Jul. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Long-term purchase commitment, time period	6 years
Proceeds from sale of extrusion assets	$ 300,000
Gain on contract termination		$ 1,600,000
Note Receivable for Sale of Assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable amount	$ 7,200,000.0
Note receivable term	4 years
Note receivable present value	$ 6,400,000	3,300,000
Note Receivable for Contract Termination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable amount			$ 2,000,000.0
Note receivable present value		$ 1,700,000	$ 1,600,000