Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance			$ 857.8
Other comprehensive (loss) income before reclassifications and tax	$ 23.8	$ 55.1	0.6	$ 52.4
Tax benefit (expense)	0.0	0.1	(0.3)	(0.7)
Other comprehensive (loss) income before reclassifications, net of tax	23.8	55.2	0.3	51.7
Reclassifications, before tax	0.6	0.1	2.3	2.5
Tax (expense) benefit	(0.2)	(0.2)	(0.5)	(1.1)
Reclassifications, net of tax	0.4	(0.1)	1.8	1.4
Other comprehensive (loss) income, net of tax	24.2	55.1	2.1	53.1
Ending Balance	872.6		872.6
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(171.9)	(159.0)	(149.8)	(157.0)
Ending Balance	(147.7)	(103.9)	(147.7)	(103.9)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(90.3)	(63.9)	(66.1)	(58.8)
Other comprehensive (loss) income before reclassifications and tax	23.7	55.5	(0.5)	50.4
Tax benefit (expense)	0.0	0.0	0.0	0.0
Other comprehensive (loss) income before reclassifications, net of tax	23.7	55.5	(0.5)	50.4
Reclassifications, before tax	0.0	0.0	0.0	0.0
Tax (expense) benefit	0.0	0.0	0.0	0.0
Reclassifications, net of tax	0.0	0.0	0.0	0.0
Other comprehensive (loss) income, net of tax	23.7	55.5	(0.5)	50.4
Ending Balance	(66.6)	(8.4)	(66.6)	(8.4)
Pension Benefits
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(81.3)	(94.3)	(82.9)	(95.1)
Other comprehensive (loss) income before reclassifications and tax	0.0	0.0	0.0	0.0
Tax benefit (expense)	0.0	0.0	0.0	0.0
Other comprehensive (loss) income before reclassifications, net of tax	0.0	0.0	0.0	0.0
Reclassifications, before tax	0.7	0.6	2.7	1.9
Tax (expense) benefit	(0.2)	(0.4)	(0.6)	(0.9)
Reclassifications, net of tax	0.5	0.2	2.1	1.0
Other comprehensive (loss) income, net of tax	0.5	0.2	2.1	1.0
Ending Balance	(80.8)	(94.1)	(80.8)	(94.1)
Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(0.3)		(0.8)
Other comprehensive (loss) income before reclassifications and tax	0.1		1.1
Tax benefit (expense)	0.0		(0.3)
Other comprehensive (loss) income before reclassifications, net of tax	0.1		0.8
Reclassifications, before tax	(0.1)		(0.4)
Tax (expense) benefit	0.0		0.1
Reclassifications, net of tax	(0.1)		(0.3)
Other comprehensive (loss) income, net of tax	0.0		0.5
Ending Balance	$ (0.3)		$ (0.3)
Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance		(0.8)		(3.1)
Other comprehensive (loss) income before reclassifications and tax		(0.4)		2.0
Tax benefit (expense)		0.1		(0.7)
Other comprehensive (loss) income before reclassifications, net of tax		(0.3)		1.3
Reclassifications, before tax		(0.5)		0.6
Tax (expense) benefit		0.2		(0.2)
Reclassifications, net of tax		(0.3)		0.4
Other comprehensive (loss) income, net of tax		(0.6)		1.7
Ending Balance		$ (1.4)		$ (1.4)