Long-Term Debt - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended	1 Months Ended	6 Months Ended	3 Months Ended
	Oct. 31, 2012	Oct. 31, 2012	Jun. 25, 2013 Senior Secured Revolving Credit Facility [Member]	Oct. 31, 2013 Senior Secured Revolving Credit Facility [Member]	Oct. 31, 2012 Second Lien Notes [Member]
Proforma Debt Instrument [Line Items]
Maturity date			Mar. 18, 2016
Debt Covenants, description				These covenants restrict fiscal year capital expenditures to 1.1 times our consolidated depreciation expense, depletion expense and landfill amortization expense, set a minimum interest coverage ratio of 2.25, a maximum consolidated total funded debt to consolidated EBITDA ratio of 5.85 and a maximum senior funded debt to consolidated EBITDA ratio of 2.50.
Ratio of restricted capital expenditure				1.1
Coverage ratio				2.25
Consolidated total funded debt to consolidated EBITDA ratio				5.85
Senior funded debt to consolidated EBITDA ratio				2.50
Loss on debt extinguishments	$ 9,670	$ 9,670			$ 9,670
Amount of refinancing 11% senior second lien notes due 2014					180,000
Debt instrument interest rate					11.00%
Debt instrument maturity year					2014
Write off of deferred financing costs					1,667
Write off discount					1,258
Charge associated with the early tender premium					$ 6,745