Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2010
Current:
U.S. - Federal									$ 173.6	$ 66.5	$ 50.3
U.S. - State									10.1	14.4	1.0
Foreign									34.0	25.0	21.2
Total current									217.7	105.9	72.5
Deferred:
U.S. - Federal									4.4	98.1	88.6
U.S. - State									1.6	2.8	(1.4)
Foreign									(5.9)	2.4	(0.3)
Total deferred									0.1	103.3	86.9
Provision for income taxes	66.7	56.0	51.1	44.0	59.7	54.9	50.4	44.2	217.8	209.2	159.4
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									209.7	200.1	167.3
Increase (Decrease) Resulting from:
Municipal lease income not taxable									(1.5)	(1.6)	(1.6)
Tax rates on foreign earnings									(6.3)	(5.5)	(3.8)
State and local income taxes, net of federal income tax benefit									7.6	11.2	(0.3)
Other - net									8.3	5.0	(2.2)
Provision for income taxes	66.7	56.0	51.1	44.0	59.7	54.9	50.4	44.2	217.8	209.2	159.4
Accumulated earnings of certain foreign subsidiaries for which no provision for U.S. income or foreign withholding taxes has been made	198.5								198.5
Cash and cash equivalents held by foreign subsidiaries	$ 51.6								$ 51.6