Goodwill and Other Intangible Assets (Narrative) (Details)	3 Months Ended	9 Months Ended
	Jan. 31, 2016 USD ($)	Apr. 30, 2017 USD ($) reporting_unit	Jul. 31, 2016 USD ($)
Indefinite-lived Intangible Assets [Line Items]
Goodwill, impairment loss	$ 0	$ 0
Number of reporting units that contain goodwill | reporting_unit		5
Reporting unit, percentage of fair value in excess of carrying amount		60.00%
Goodwill		$ 229,600,000	$ 229,300,000
Fair value inputs, long-term revenue growth rate	3.00%
Fair value inputs, discount rate	11.50%
Goodwill, impairment test, benchmark residual growth rate decrease that would result in potential impairment, percent	3.00%
Goodwill, impairment test, benchmark discount rate increase that would result in potential impairment, percent	0.00%
Goodwill, impairment test, benchmark projected cash flow decrease that would result in potential impairment, percent	1.50%
Intangible assets, net		38,500,000	$ 38,500,000
Goodwill, foreign currency translation gain (loss)		(800,000)
Partmo
Indefinite-lived Intangible Assets [Line Items]
Amount of finite-lived intangibles acquired		4,700,000
Amortization of existing intangible assets		4,300,000
Goodwill, foreign currency translation gain (loss)		$ (400,000)
Customer Relationships | Partmo
Indefinite-lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		20 years
Trade Names | Partmo
Indefinite-lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		10 years
Gas Turbine Systems
Indefinite-lived Intangible Assets [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount		15.00%
Goodwill		$ 60,400,000