Fair Value of Financial Instruments - Schedule of Fair Value of Financial Instruments (Details) $ in Millions		3 Months Ended	6 Months Ended
		Apr. 30, 2017 USD ($)	Apr. 30, 2017 USD ($) contingent_consideration_liability	Apr. 30, 2016 USD ($)	Oct. 31, 2016 USD ($) contingent_consideration_liability
Financial Instruments
Number of contingent consideration liabilities | contingent_consideration_liability					1
Payment for contingent consideration		$ 3.8	$ 3.8	$ 0.0
Number of contingent consideration liabilities recorded during period | contingent_consideration_liability			1
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Financial Instruments
Cash and cash equivalents	[1]	55.7	$ 55.7		$ 53.5
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Other Noncurrent Assets
Financial Instruments
Assets held in funded deferred compensation plan	[2]	5.0	5.0		4.9
Insurance deposits	[3]	11.2	11.2		11.2
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Financial Instruments
Line of credit	[4]	277.9	277.9		268.3
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Other Noncurrent Assets
Financial Instruments
Interest rate swaps	[5]	2.8	2.8		0.2
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Other Investments
Financial Instruments
Investments in auction rate securities	[6]	8.0	8.0		8.0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Other Noncurrent Liabilities
Financial Instruments
Contingent consideration liability	[7]	$ 0.9	$ 0.9		$ 3.8

[1] Cash and cash equivalents are stated at nominal value, which equals fair value.

[2] Represents investments held in a Rabbi trust associated with one of our deferred compensation plans, which we include in “Other noncurrent assets” on the accompanying unaudited consolidated balance sheets. The fair value of the assets held in the funded deferred compensation plan is based on quoted market prices.

[3] Represents restricted insurance deposits that are used to collateralize our insurance obligations and are stated at nominal value, which equals fair value. These insurance deposits are included in “Other noncurrent assets” on the accompanying unaudited consolidated balance sheets. See Note 10, “Insurance,” for further information.

[4] Represents outstanding borrowings under our syndicated line of credit. Due to variable interest rates, the carrying value of outstanding borrowings under our line of credit approximates the fair value. See Note 11, “Line of Credit,” for further information.

[5] Represents interest rate swap derivatives designated as cash flow hedges. The fair values of the interest rate swaps are estimated based on the present value of the difference between expected cash flows calculated at the contracted interest rates and the expected cash flows at current market interest rates using observable benchmarks for LIBOR forward rates at the end of the period. These interest rate swaps are included in “Other noncurrent assets” on the accompanying unaudited consolidated balance sheets. See Note 11, “Line of Credit,” for further information.

[6] For investments in auction rate securities, the fair value was based on discounted cash flow valuation models, primarily utilizing unobservable inputs, including assumptions about the underlying collateral, credit risks associated with the issuer, credit enhancements associated with financial insurance guarantees, and the possibility of the security being re-financed by the issuer or having a successful auction. These amounts are included in “Other investments” on the accompanying unaudited consolidated balance sheets. See Note 9, “Auction Rate Securities,” for further information.

[7] Certain of our acquisitions involve the payment of contingent consideration. The fair value of these liabilities is based on the expected achievement of certain pre-established revenue goals. At October 31, 2016, we had one contingent consideration liability included in “Other accrued liabilities” on the accompanying unaudited consolidated balance sheets. During the three months ended April 30, 2017, the income-related target for that acquisition was achieved, resulting in the payment of $3.8 million to the seller. In connection with the MSI acquisition, we recorded one new contingent consideration liability during 2017, which is included in “Other noncurrent liabilities” on the accompanying unaudited consolidated balance sheets.