Fair Value of Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) $ in Millions		9 Months Ended
		Jul. 31, 2017 USD ($) contingent_consideration_liability	Jul. 31, 2016 USD ($)	Oct. 31, 2016 USD ($) contingent_consideration_liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of contingent consideration liabilities | contingent_consideration_liability				1
Payment for contingent consideration		$ 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
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	[1]	$ 47.7		$ 53.5
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Other Noncurrent Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets held in funded deferred compensation plan	[2]	4.5		4.9
Insurance deposits	[3]	11.2		11.2
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of credit	[4]	264.7		268.3
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Other Noncurrent Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	[5]	2.4		0.2
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Other Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in auction rate securities	[6]	8.0		8.0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Other Noncurrent Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	[7]	$ 0.9
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Other Accrued Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	[7]			$ 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 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 9, “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 10, “Credit Facility,” 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 10, “Credit Facility,” for further information.

[6] The fair value of investments in auction rate securities is 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 8, “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 nine months ended July 31, 2017, the revenue-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.