Income Taxes - Summary Of Income Tax Examinations (Detail)	12 Months Ended
	Jul. 31, 2019
United States – Federal | Maximum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2018
United States – Federal | Minimum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2016
United States – State | Maximum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2018
United States – State | Minimum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2016
Germany | Maximum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2018
Germany | Minimum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2016
France | Maximum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2018
France | Minimum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2016
Italy | Maximum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2018
Italy | Minimum [Member]
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2015
United Kingdom
Income Tax Examination [Line Items]
Income Tax Examination, Year under Examination	2018