Long Term Debt (Details) (USD $)	12 Months Ended					12 Months Ended			1 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		7 Months Ended	12 Months Ended		7 Months Ended	12 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2009	Oct. 31, 2011 Insured Quarterly Notes 6.25% Due 2036 [Member]	Oct. 31, 2010 Insured Quarterly Notes 6.25% Due 2036 [Member]	Oct. 31, 2011 Retirement Of Principal Payments [Member]	Oct. 31, 2010 Retirement Of Principal Payments [Member]	Oct. 31, 2011 Redemption Of Insured Quarterly Notes [Member]	Sep. 30, 2010 Medium Term Notes 7.80% Due 2010 [Member]	Sep. 30, 2011 Medium Term Notes 6.55% Due 2011 [Member]	Oct. 31, 2011 Medium Term Notes 6.55% Due 2011 [Member]	Oct. 31, 2010 Medium Term Notes 6.55% Due 2011 [Member]	Oct. 31, 2011 Medium Term Notes 5.00% Due 2013 [Member]	Oct. 31, 2010 Medium Term Notes 5.00% Due 2013 [Member]	Oct. 31, 2011 Medium Term Notes 6.87% Due 2023 [Member]	Oct. 31, 2010 Medium Term Notes 6.87% Due 2023 [Member]	Oct. 31, 2011 Medium Term Notes 8.45% Due 2024 [Member]	Oct. 31, 2010 Medium Term Notes 8.45% Due 2024 [Member]	Oct. 31, 2011 Medium Term Notes 7.40% Due 2025 [Member]	Oct. 31, 2010 Medium Term Notes 7.40% Due 2025 [Member]	Oct. 31, 2011 Medium Term Notes 7.50% Due 2026 [Member]	Oct. 31, 2010 Medium Term Notes 7.50% Due 2026 [Member]	Oct. 31, 2011 Medium Term Notes 7.95% Due 2029 [Member]	Oct. 31, 2010 Medium Term Notes 7.95% Due 2029 [Member]	Oct. 31, 2011 Medium Term Notes 6.00% Due 2033 [Member]	Oct. 31, 2010 Medium Term Notes 6.00% Due 2033 [Member]	Oct. 31, 2011 Senior Notes 8.51% Due 2017 [Member]	Oct. 31, 2010 Senior Notes 8.51% Due 2017 [Member]	Jun. 06, 2011 Senior Notes 2.92% Due 2016 [Member]	Oct. 31, 2011 Senior Notes 2.92% Due 2016 [Member]	Oct. 31, 2010 Senior Notes 2.92% Due 2016 [Member]	Jun. 06, 2011 Senior Notes 4.24% Due 2021 [Member]	Oct. 31, 2011 Senior Notes 4.24% Due 2021 [Member]	Oct. 31, 2010 Senior Notes 4.24% Due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	$ 675,000,000	$ 731,922,000		$ 0	$ 196,922,000						$ 0	$ 60,000,000	$ 100,000,000	$ 100,000,000	$ 45,000,000	$ 45,000,000	$ 40,000,000	$ 40,000,000	$ 55,000,000	$ 55,000,000	$ 40,000,000	$ 40,000,000	$ 60,000,000	$ 60,000,000	$ 100,000,000	$ 100,000,000	$ 35,000,000	$ 35,000,000		$ 40,000,000	$ 0		$ 160,000,000	$ 0
Debt Instrument Interest Rate Stated Percentage				6.25%							6.55%		5.00%		6.87%		8.45%		7.40%		7.50%		7.95%		6.00%		8.51%		2.92%	2.92%		4.24%	4.24%
Debt Instrument Maturity Date				Jun. 01, 2011							Sep. 26, 2011		Dec. 19, 2013		Oct. 06, 2023		Sep. 19, 2024		Oct. 03, 2025		Oct. 09, 2026		Sep. 14, 2029		Dec. 19, 2033		Sep. 30, 2017			Jun. 06, 2016			Jun. 06, 2021
Current maturities of long-term debt	0	60,000,000
Long-term debt	675,000,000	671,922,000
Maturities Of Long Term Debt Abstract
Long Term Debt Maturities Repayments Of Principal In Next Twelve Months	0
Long Term Debt Maturities Repayments Of Principal In Year Two	0
Long Term Debt Maturities Repayments Of Principal In Year Three	100,000,000
Long Term Debt Maturities Repayments Of Principal In Year Four	0
Long Term Debt Maturities Repayments Of Principal In Year Five	40,000,000
Long Term Debt Maturities Repayments Of Principal After Year Five	535,000,000
Retirement of long-term debt	256,922,000	60,590,000	31,749,000			79,000	590,000	196,843,000	60,000,000	60,000,000
Proceeds from issuance of unsecured debt																													40,000,000			160,000,000
Net Earnings Available For Restricted Payments	605,481,000
Retained earnings	$ 550,584,000	$ 519,831,000