Schedule II Valuation of Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balances at beginning of period	$ 3,069	$ 5,093	$ 6,005
Additions — Charged to expense	1,954	779	1,018
Due to acquired businesses	0	0	531
Reclassified to continuing operations	0	31	0
Deductions - written off	(1,438)	(2,834)	(1,429)
Deductions — Reclassified to discontinued operations	0	0	(1,032)
Balances at end of period	3,585	3,069	5,093
Inventory Valuation Reserve [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balances at beginning of period	12,259	11,317	11,316
Additions — Charged to expense	3,017	3,100	2,629
Due to acquired businesses	0	0	2,887
Reclassified to continuing operations	0	461	0
Deductions - written off	(2,007)	(2,619)	(1,811)
Deductions — Reclassified to discontinued operations	0	0	(3,704)
Balances at end of period	13,269	12,259	11,317
Valuation Allowance of Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balances at beginning of period	37,409	37,142	25,847
Additions — Charged to expense	8,111	10,182	10,853
Due to acquired businesses	0	0	983
Deductions - written off	(5,598)	(9,915)	(541)
Balances at end of period	$ 39,922	$ 37,409	$ 37,142