Commitments And Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013	Jul. 14, 2015
Commitments And Contingencies [Line Items]
Total expense	$ 28,100				$ 28,000				$ 28,100	$ 28,000	$ 27,500
2016	11,400								11,400
2017	7,400								7,400
2018	5,100								5,100
2019	2,800								2,800
2020	1,000								1,000
Thereafter	200								200
Annual sales	$ 610,578	$ 575,588	$ 588,537	$ 596,510	$ 668,226	$ 624,234	$ 581,622	$ 599,384	2,371,213	$ 2,473,466	$ 2,436,948
Industrias Partmo S.a. [Member]
Commitments And Contingencies [Line Items]
Percentage of shares to be acquired												100.00%
Annual sales									$ 15,000