Consolidated Statements Of Income (USD $)	12 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2009
Income Statement [Abstract]
Operating Revenues	$ 1,433,905,000	$ 1,552,295,000	$ 1,638,116,000
Cost of Gas	860,266,000	999,703,000	1,076,542,000
Margin	573,639,000	552,592,000	561,574,000
Operating Expenses
Operations and maintenance	225,351,000	219,829,000	208,105,000
Depreciation	102,829,000	98,494,000	97,425,000
General taxes	38,380,000	33,909,000	34,590,000
Utility income taxes	64,068,000	62,082,000	70,079,000
Total operating expenses	430,628,000	414,314,000	410,199,000
Operating Income	143,011,000	138,278,000	151,375,000
Other Income (Expense)
Income from equity method investments	24,027,000	28,854,000	33,464,000
Gain on sale of interest in equity method investment	0	49,674,000	0
Non-operating income	1,762,000	659,000	32,000
Charitable contributions	(1,818,000)	(1,363,000)	(2,011,000)
Non-operating expense	(1,204,000)	(643,000)	(1,558,000)
Non-operating income taxes	(8,218,000)	(29,794,000)	(11,803,000)
Total other income (expense)	14,549,000	47,387,000	18,124,000
Utility Interest Charges
Interest on long-term debt	46,070,000	52,666,000	55,105,000
Allowance for borrowed funds used during construction	(8,619,000)	(9,981,000)	(2,298,000)
Other interest	6,541,000	1,026,000	(6,132,000)
Total utility interest charges	43,992,000	43,711,000	46,675,000
Net Income	$ 113,568,000	$ 141,954,000	$ 122,824,000
Average Shares of Common Stock
Basic	72,056,000	72,275,000	73,171,000
Diluted	72,266,000	72,525,000	73,461,000
Earnings Per Share [Abstract]
Basic EPS	$ 1.58	$ 1.96	$ 1.68
Diluted EPS	$ 1.57	$ 1.96	$ 1.67