Net Income Per Common Share - Calculations of Basic and Diluted Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended												12 Months Ended
	Oct. 31, 2016		Jul. 31, 2016		Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015		Jul. 31, 2015		Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2016	Oct. 31, 2015		Oct. 31, 2014
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Income from continuing operations	$ 9.0		$ 32.9		$ 6.8	$ 13.6	$ 22.6		$ 1.2		$ 16.0	$ 14.3	$ 62.3	$ 54.1		$ 66.9
Net (loss) income from discontinued operations	(1.2)		(1.8)		(2.4)	0.4	16.2		0.3		2.3	3.4	(5.1)	22.2	[1]	8.7
Net income	$ 7.8	[2]	$ 31.1	[3]	$ 4.4	$ 14.0	$ 38.8	[4]	$ 1.5	[5]	$ 18.3	$ 17.7	$ 57.2	$ 76.3		$ 75.6
Weighted-average common and common equivalent shares outstanding—Basic (in shares)													56.3	56.7		56.1
Effect of dilutive securities
Weighted-average common and common equivalent shares outstanding—Diluted (in shares)													56.9	57.4		57.1
Net income per common share — Basic
Income from continuing operations (in usd per share)	$ 0.16		$ 0.58		$ 0.12	$ 0.24	$ 0.39		$ 0.02		$ 0.28	$ 0.25	$ 1.11	$ 0.95		$ 1.19
Income from discontinued operations (in usd per share)	(0.02)		(0.03)		(0.04)	0.01	0.29		0.01		0.04	0.06	(0.09)	0.40		0.16
Net income per common share-Basic (in usd per share)	0.14		0.55		0.08	0.25	0.68		0.03		0.32	0.31	1.02	1.35		1.35
Net income per common share — Diluted
Income from continuing operations (in usd per share)	0.16		0.58		0.12	0.24	0.39		0.02		0.28	0.25	1.09	0.94		1.17
Income from discontinued operations (in usd per share)	(0.02)		(0.03)		(0.04)	0.00	0.29		0.01		0.04	0.06	(0.09)	0.39		0.15
Net income per common share-Diluted (in usd per share)	$ 0.14	[2]	$ 0.55	[3]	$ 0.08	$ 0.24	$ 0.68	[4]	$ 0.03	[5]	$ 0.32	$ 0.31	$ 1.01	$ 1.33		$ 1.32
RSUs
Effect of dilutive securities
Effect of dilutive securities (in shares)													0.3	0.3		0.4
Stock options
Effect of dilutive securities
Effect of dilutive securities (in shares)													0.2	0.3		0.4
Performance shares
Effect of dilutive securities
Effect of dilutive securities (in shares)													0.1	0.1		0.2

[1] Includes a $1.6 million unfavorable legal settlement related to our former Lighting segment, which we disposed of in 2008.

[2] Includes goodwill and asset impairment charges of $22.5 million, or $0.40 per diluted share, associated with our held-for-sale Government Services business.

[3] Includes a tax benefit of $19.0 million, or $0.33 per diluted share, related to a lapse of statutes of limitations.

[4] Reflects the after-tax gain on sale of our Security business of $14.4 million, or $0.25 per diluted share.

[5] Includes an unfavorable adjustment to our self-insurance reserves for prior year claims of $35.9 million, or $0.62 per diluted share.