Intangible Assets (Intangible Assets with Finite Lives) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020	Jul. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 418,333,000		$ 418,333,000		$ 418,233,000
Accumulated Amortization	170,575,000		170,575,000		160,214,000
Net Carrying Amount	247,758,000		247,758,000		$ 258,019,000
Amortization of intangibles	4,795,000	$ 5,229,000	$ 10,361,000	$ 10,435,000
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period			20 years 4 months 24 days		20 years 4 months 24 days
Gross Carrying Amount	286,558,000		$ 286,558,000		$ 286,058,000
Accumulated Amortization	86,162,000		86,162,000		79,534,000
Net Carrying Amount	200,396,000		$ 200,396,000		$ 206,524,000
Technologies
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period			14 years		14 years
Gross Carrying Amount	99,649,000		$ 99,649,000		$ 99,349,000
Accumulated Amortization	68,433,000		68,433,000		65,398,000
Net Carrying Amount	31,216,000		$ 31,216,000		$ 33,951,000
Trademarks and other
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period			16 years 7 months 6 days		16 years 7 months 6 days
Gross Carrying Amount	32,126,000		$ 32,126,000		$ 32,826,000
Accumulated Amortization	15,980,000		15,980,000		15,282,000
Net Carrying Amount	$ 16,146,000		$ 16,146,000		$ 17,544,000