CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 134,830	$ 101,572
Adjustments to reconcile net income to cash flows from operating activities:
Unrealized (gain) loss on derivative instruments	(23,683)	17,596
Depreciation and amortization	34,966	30,726
Allowance for equity used during construction	(1,926)	(317)
Allowance for bad debt expense	1,829	1,989
Deferred income taxes	23,406	30,588
Manufactured gas plant remediation costs	(5,326)	(6,125)
Equity in earnings of affiliates, net of distributions received	(1,050)	4,209
Cost of removal - asset retirement obligations	(926)	(912)
Contributions to postemployment benefit plans	(24,538)	(24,446)
Changes in:
Components of working capital	(22,092)	(110,114)
Other noncurrent assets	(2,607)	8,747
Other noncurrent liabilities	12,256	6,404
Cash flows from operating activities	125,139	59,917
CASH FLOWS (USED IN) INVESTING ACTIVITIES
Utility plant expenditures	(73,654)	(71,916)
Solar equipment expenditures	(39,756)	(75,243)
Real estate properties and other expenditures	(532)	(568)
Cost of removal expenditures	(21,186)	(10,634)
Distribution from equity investees	2,107	0
Proceeds from sale of available-for-sale securities	482	0
Withdrawal from restricted cash construction fund	0	126
Cash flows (used in) investing activities	(132,539)	(158,235)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of common stock	10,581	10,636
Tax benefit from stock options exercised	110	222
Proceeds from sale-leaseback transaction	7,076	6,522
Proceeds from long-term debt	50,000	0
Payments of long-term debt	(5,808)	(4,856)
Purchases of treasury stock	(23,689)	(8,768)
Payments of common stock dividends	(50,619)	(46,466)
Net proceeds from short-term debt	17,100	140,650
Cash flows from financing activities	4,751	97,940
Change in cash and cash equivalents	(2,649)	(378)
Cash and cash equivalents at beginning of period	4,509	7,440
Cash and cash equivalents at end of period	1,860	7,062
CHANGES IN COMPONENTS OF WORKING CAPITAL
Receivables	(120,719)	36,598
Inventories	(24,792)	78,601
Recovery of gas costs	4,994	(13,405)
Gas purchases payable	86,932	(99,173)
Prepaid and accrued taxes	20,059	(11,375)
Accounts payable and other	(6,385)	9,754
Restricted broker margin accounts	26,760	(20,320)
Customers' credit balances and deposits	(30,899)	(75,318)
Other current assets	21,958	(15,476)
Components of working capital	(22,092)	(110,114)
SUPPLEMENTAL DISCLOSURES OF CASH FLOWS INFORMATION
Cash paid for Interest (net of amounts capitalized)	11,121	8,918
Cash paid for Income taxes	9,539	7,536
SUPPLEMENTAL SCHEDULE OF NONCASH INVESTING ACTIVITIES
Accrued capital expenditures	$ (9,734)	$ (108)