Fair Value of Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) $ in Millions		12 Months Ended
		Oct. 31, 2017 USD ($) contingent_consideration_liability	Oct. 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
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]	$ 62.8	$ 39.1
Insurance deposits	[2]	11.2	0.6
Assets held in funded deferred compensation plan	[3]	4.6	2.7
Fair Value Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility	[4]	1,191.2	949.0
Interest rate swaps	[5]	2.9	1.3
Fair Value Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in auction rate securities	[6]	8.0	5.0
Contingent consideration liability	[7]	$ 0.9	$ 0.0

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

[2] 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 consolidated balance sheets. See Note 11, “Insurance,” for further information.

[3] 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 consolidated balance sheets. The fair value of the assets held in the funded deferred compensation plan is based on quoted market prices. See Note 13, “Employee Benefit Plans,” for further information.

[4] Represents gross outstanding borrowings under our syndicated line of credit and term loan. Due to variable interest rates, the carrying value of outstanding borrowings under our line of credit and term loan approximates the fair value. See Note 12, “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. During April 2018, we elected to terminate our interest rate swaps and recognized a gain in AOCI. We subsequently entered into new forward starting interest rate swaps. See Note 12, “Credit Facility,” for further information. Our interest rate swaps are included in “Other noncurrent assets” on the accompanying consolidated balance sheets.

[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 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. In connection with the MSI acquisition during 2017, we recorded one new contingent consideration liability. Based on the metrics of the underlying pre-established revenue goals, this contingent consideration liability was reduced to a nominal value at October 31, 2018. This contingent consideration liability is included on the accompanying consolidated balance sheets in “Other noncurrent liabilities” at October 31, 2017.