CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($)	Mar. 31, 2018	Sep. 30, 2017
ASSETS
Property, plant and equipment	$ 11,903,715,000	$ 11,301,304,000
Less accumulated depreciation and amortization	2,142,386,000	2,042,122,000
Net property, plant and equipment	9,761,329,000	9,259,182,000
Current assets
Cash and cash equivalents	71,074,000	26,409,000
Accounts receivable, net	407,134,000	222,263,000
Gas stored underground	89,265,000	184,653,000
Other current assets	55,263,000	106,321,000
Total current assets	622,736,000	539,646,000
Goodwill	730,132,000	730,132,000
Deferred charges and other assets	242,125,000	220,636,000
Total assets	11,356,322,000	10,749,596,000
Shareholders' equity
Common stock, no par value (stated at $.005 per share)	555,000	531,000
Additional paid-in capital	2,951,545,000	2,536,365,000
Accumulated other comprehensive income (loss)	(85,011,000)	(105,254,000)
Retained earnings	1,854,257,000	1,467,024,000
Shareholders' equity	4,721,346,000	3,898,666,000
Long-term debt	2,617,892,000	3,067,045,000
Total capitalization	7,339,238,000	6,965,711,000
Current liabilities
Accounts payable and accrued liabilities	230,823,000	233,050,000
Other current liabilities	538,702,000	332,648,000
Short-term debt	129,602,000	447,745,000
Current maturities of long-term debt	450,000,000	0
Total current liabilities	1,349,127,000	1,013,443,000
Deferred income taxes	1,107,036,000	1,878,699,000
Regulatory Liability, Excess Deferred Tax	737,798,000	0
Regulatory cost of removal obligation	484,746,000	485,420,000
Pension and postretirement liabilities	237,448,000	230,588,000
Deferred credits and other liabilities	100,929,000	175,735,000
Total shareholders' equity and liabilities	$ 11,356,322,000	$ 10,749,596,000