Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2013
Current:
U.S. - Federal									$ 119.1	$ 274.4	$ 174.6
U.S. - State									5.4	7.9	6.8
Foreign									20.1	21.2	32.6
Total current									144.6	303.5	214.0
Deferred:
U.S. - Federal									121.2	(33.7)	42.4
U.S. - State									1.7	0.6	0.8
Foreign									2.4	(9.8)	1.2
Total deferred									125.3	(42.9)	44.4
Provision for income taxes	$ 64.4	$ 71.1	$ 67.7	$ 66.7	$ 79.9	$ 71.6	$ 70.6	$ 38.5	$ 269.9	260.6	258.4
Comparison of the Statutory and Effective Income Tax Provision
U.S. federal income tax provision statutory rate (as a percent)									35.00%
U.S. federal income tax provision at a statutory rate of 35 percent									$ 268.4	281.0	254.0
Increase (Decrease) Resulting from:
Municipal lease income not taxable									(1.4)	(1.4)	(1.4)
Tax rates on foreign earnings									(6.0)	(8.0)	(7.2)
Foreign tax benefit										(23.1)
State and local income taxes, net of federal income tax benefit									4.6	5.5	4.9
Other - net									4.3	6.6	8.1
Provision for income taxes	64.4	$ 71.1	$ 67.7	$ 66.7	$ 79.9	$ 71.6	$ 70.6	$ 38.5	269.9	$ 260.6	$ 258.4
Accumulated earnings of certain subsidiaries outside the U.S. for which no provision for U.S. income or foreign withholding taxes has been made	340.9								340.9
Provision for income and withholding taxes on accumulated earnings in certain subsidiaries outside the U.S.	0.0								0.0
Cash and cash equivalents held by foreign subsidiaries	$ 110.1								$ 110.1