Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income, Net of Taxes	Retained Earnings
Balance, beginning of year (in shares) at Oct. 31, 2017		65.5
Balance, beginning of year at Oct. 31, 2017		$ 0.7	$ 675.2	$ (20.3)	$ 720.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued under employee stock purchase and share-based compensation plans (in shares)		0.2
Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans, net		$ 0.0	(0.4)
Share-based compensation expense			8.3
Other comprehensive (loss) income				21.9
Net income	$ 54.4				54.4
Dividends
Common stock ($0.180, $0.175, $0.360, and $0.350 per share)					(23.0)
Stock issued under share-based compensation plans					(0.3)
Balance, end of year (in shares) at Apr. 30, 2018		65.7
Balance, end of year at Apr. 30, 2018	$ 1,436.6	$ 0.7	683.1	1.6	751.2
Dividends
Common stock, dividends (in usd per share)	$ 0.350
Balance, beginning of year (in shares) at Jan. 31, 2018		65.7
Balance, beginning of year at Jan. 31, 2018		$ 0.7	677.1	2.7	736.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued under employee stock purchase and share-based compensation plans (in shares)		0.0
Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans, net		$ 0.0	1.4
Share-based compensation expense			4.5
Other comprehensive (loss) income				(1.1)
Net income	$ 26.6				26.6
Dividends
Common stock ($0.180, $0.175, $0.360, and $0.350 per share)					(11.5)
Stock issued under share-based compensation plans					(0.1)
Balance, end of year (in shares) at Apr. 30, 2018		65.7
Balance, end of year at Apr. 30, 2018	$ 1,436.6	$ 0.7	683.1	1.6	751.2
Dividends
Common stock, dividends (in usd per share)	$ 0.175
Balance, beginning of year (in shares) at Oct. 31, 2018		66.0
Balance, beginning of year at Oct. 31, 2018	$ 1,454.6	$ 0.7	691.8	(9.0)	771.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued under employee stock purchase and share-based compensation plans (in shares)		0.3
Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans, net		$ 0.0	0.0
Share-based compensation expense			8.8
Other comprehensive (loss) income				(6.7)
Net income	42.7				42.7
Dividends
Common stock ($0.180, $0.175, $0.360, and $0.350 per share)					(23.8)
Stock issued under share-based compensation plans					(0.7)
Balance, end of year (in shares) at Apr. 30, 2019		66.3
Balance, end of year at Apr. 30, 2019	$ 1,481.4	$ 0.7	700.6	(15.7)	795.9
Dividends
Common stock, dividends (in usd per share)	$ 0.360
Balance, beginning of year (in shares) at Jan. 31, 2019		66.2
Balance, beginning of year at Jan. 31, 2019		$ 0.7	694.1	(12.2)	778.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued under employee stock purchase and share-based compensation plans (in shares)		0.1
Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans, net		$ 0.0	2.2
Share-based compensation expense			4.3
Other comprehensive (loss) income				(3.4)
Net income	$ 29.7				29.7
Dividends
Common stock ($0.180, $0.175, $0.360, and $0.350 per share)					(11.9)
Stock issued under share-based compensation plans					(0.5)
Balance, end of year (in shares) at Apr. 30, 2019		66.3
Balance, end of year at Apr. 30, 2019	$ 1,481.4	$ 0.7	$ 700.6	$ (15.7)	$ 795.9
Dividends
Common stock, dividends (in usd per share)	$ 0.180