Restructuring and Other Related Charges (Restructuring and Other Related Liabilities) (Details) $ in Millions	9 Months Ended
	May 02, 2020 USD ($)
Restructuring Reserve [Roll Forward]
Balance at August 3, 2019	$ 12.4
Additions charged to expense	2.1
Cash payments	(12.0)
Balance at May 2, 2020	2.5
Severance and benefit costs
Restructuring Reserve [Roll Forward]
Balance at August 3, 2019	11.4
Additions charged to expense	1.6
Cash payments	(10.5)
Balance at May 2, 2020	2.5
Other related charges
Restructuring Reserve [Roll Forward]
Balance at August 3, 2019	1.0
Additions charged to expense	0.5
Cash payments	(1.5)
Balance at May 2, 2020	$ 0.0