Acquisitions and Divestitures - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended				12 Months Ended			12 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended
	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012	Dec. 28, 2012	Jul. 31, 2014 Finite-lived customer relationships [Member]	Jul. 31, 2014 Trademarks [Member]	Jul. 31, 2014	Jul. 31, 2013 Precision Dynamics Corporation [Member]	Jul. 31, 2012 Precision Dynamics Corporation [Member]	Dec. 28, 2012 Precision Dynamics Corporation [Member]	Jul. 31, 2012 Grafo [Member]	Apr. 30, 2012 Grafo [Member]	Jul. 31, 2012 Runelandhs [Member]	Jul. 31, 2013 Runelandhs [Member]	Jul. 31, 2012 Pervaco [Member]	Jul. 31, 2013 Pervaco [Member]	Jul. 31, 2012 Pervaco [Member]	Jul. 31, 2012 Runelandhs [Member]	Jul. 31, 2012 Grafo [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Business Combination, Acquisition Related Costs																$ 3,600	$ 3,600
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory																1,530	1,530
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination																			3,039		22,499		12,111
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period																			3,000		19,000		6,000
Goodwill, Acquired During Period										170,180															8,440	13,177	1,227
Indefinite-Lived Trade Names																						5,340	6,878	1,538
Notes Payable															19,422
Proceeds from sale of operations									54,242	10,178	856
Loss (gain) on sales of businesses									1,238	3,138	204
Net sales	316,733	309,577	291,194	307,530	310,592	302,483	272,702	272,015	1,225,034	1,157,792	1,071,504
Net (loss) income, as reported									(45,968)	(154,535)	(17,911)
Proceeds from borrowing on notes payable									63,000	220,000	0
Repayment of borrowing on notes payable									2,398	0	0
Customer relationships																		102,500		961		5,474	8,903	2,468
Finite-Lived Intangible Asset, Useful Life											7 years		10 years	3 years
Finite-Lived Trade Names, Gross												6,800
Interest Expense									14,300	16,641	19,090					529	1,402
Income tax expense (benefit)									(4,963)	42,583	37,162					(429)	2,526
Amortization of Intangible Assets									17,871	17,148	10,576					5,215	12,517
Finite-Lived Noncompete Agreements, Gross																						95	186	91
Business Acquisition, Purchase Price Allocation, Goodwill, Expected Tax Deductible Amount																		57,374
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill																		$ 51,672