Intangibles and Goodwill - Intangible Assets Summary (Details) - USD ($)	3 Months Ended		6 Months Ended
	Oct. 31, 2016	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016	Jul. 31, 2016
Intangible assets with finite lives:
Amortization expense	$ 4,057,000	$ 3,297,000	$ 7,966,000	$ 6,391,000
Gross			169,866,000		$ 145,210,000
Accumulated Amortization			(48,713,000)		(41,002,000)
Net			121,153,000		104,208,000
Intangible assets with indefinite lives:
Trademarks and tradenames			7,514,000		7,511,000
Total intangible assets
Gross			177,380,000		152,721,000
Accumulated Amortization			(48,713,000)		(41,002,000)
Net			$ 128,667,000		111,719,000
Minimum
Intangible assets with finite lives:
Estimated useful lives			3 years
Maximum
Intangible assets with finite lives:
Estimated useful lives			20 years
Weighted average
Intangible assets with finite lives:
Estimated useful lives			12 years
Customer relationships
Intangible assets with finite lives:
Gross			$ 113,700,000		100,649,000
Accumulated Amortization			(29,434,000)		(24,689,000)
Net			84,266,000		75,960,000
Total intangible assets
Accumulated Amortization			(29,434,000)		(24,689,000)
Technology
Intangible assets with finite lives:
Gross			42,261,000		32,767,000
Accumulated Amortization			(14,166,000)		(11,813,000)
Net			28,095,000		20,954,000
Total intangible assets
Accumulated Amortization			(14,166,000)		(11,813,000)
Brand names
Intangible assets with finite lives:
Gross			8,119,000		6,194,000
Accumulated Amortization			(2,819,000)		(2,394,000)
Net			5,300,000		3,800,000
Total intangible assets
Accumulated Amortization			(2,819,000)		(2,394,000)
Non-compete agreements
Intangible assets with finite lives:
Gross			3,092,000		3,092,000
Accumulated Amortization			(1,311,000)		(1,193,000)
Net			1,781,000		1,899,000
Total intangible assets
Accumulated Amortization			(1,311,000)		(1,193,000)
Patents and other registrations
Intangible assets with finite lives:
Gross			2,694,000		2,508,000
Accumulated Amortization			(983,000)		(913,000)
Net			1,711,000		1,595,000
Total intangible assets
Accumulated Amortization			$ (983,000)		$ (913,000)