Segment Information (Tables)

3 Months Ended

Dec. 31, 2012

Segment Reporting [Abstract]

Segment Information

Financial information by business segment follows:

Three Months EndedDecember 31, 2012:

			Reportable Segments
	Total		Gas Utility		Electric Utility		Other
Revenues	$	273,797	$	248,254	$	25,118	$	425
Cost of sales	$	138,277	$	123,574	$	14,703	$	—
Depreciation and amortization	$	13,571	$	12,605	$	966	$	—
Operating income	$	72,564	$	69,789	$	2,624	$	151
Interest expense	$	10,077	$	9,572	$	505	$	—
Income before income taxes	$	62,487	$	60,217	$	2,119	$	151
Total assets (at period end)	$	2,319,704	$	2,164,368	$	155,336	$	—
Goodwill (at period end)	$	182,145	$	182,145	$	—	$	—
Capital expenditures	$	29,728	$	28,519	$	1,209	$	—

Three Months EndedDecember 31, 2011:

			Reportable Segments
	Total		Gas Utility		Electric Utility		Other
Revenues	$	280,641	$	255,030	$	25,169	$	442
Cost of sales	$	156,906	$	141,679	$	15,227	$	—
Depreciation and amortization	$	13,063	$	12,145	$	918	$	—
Operating income	$	64,605	$	61,231	$	3,230	$	144
Interest expense	$	10,607	$	10,098	$	509	$	—
Income before income taxes	$	53,998	$	51,133	$	2,721	$	144
Total assets (at period end)	$	2,238,458	$	2,088,710	$	149,748	$	—
Goodwill (at period end)	$	182,145	$	182,145	$	—	$	—
Capital expenditures	$	22,858	$	21,812	$	1,046	$	—