Segment Information (Tables)

12 Months Ended

Sep. 30, 2017

Segment Reporting [Abstract]

Segment Information

Financial information by business segment follows:

	Total		Gas Utility		Electric Utility		Other
2017
Revenues	$	887,588	$	799,054	$	88,534
Cost of sales	$	367,279	$	318,210	$	49,069
Depreciation and amortization	$	72,332	$	67,357	$	4,975
Operating income	$	228,307	$	219,561	$	8,746
Interest expense	$	40,212	$	38,218	$	1,994
Income before income taxes	$	188,095	$	181,343	$	6,752
Total assets	$	2,994,015	$	2,833,423	$	160,592
Goodwill	$	182,145	$	182,145	$	—
Capital expenditures (including the effects of accruals)	$	317,722	$	306,243	$	11,479
2016
Revenues	$	768,484	$	677,387	$	91,097
Cost of sales	$	289,786	$	239,163	$	50,623
Depreciation and amortization	$	67,303	$	62,451	$	4,852
Operating income	$	200,901	$	189,412	$	11,489
Interest expense	$	37,630	$	35,786	$	1,844
Income before income taxes	$	163,271	$	153,626	$	9,645
Total assets	$	2,743,091	$	2,570,297	$	172,794
Goodwill	$	182,145	$	182,145	$	—
Capital expenditures (including the effects of accruals)	$	262,503	$	251,261	$	11,242
2015
Revenues	$	1,041,581	$	933,080	$	107,577	$	924
Cost of sales	$	510,784	$	448,617	$	62,167	$	—
Depreciation and amortization	$	63,590	$	58,974	$	4,616	$	—
Operating income	$	241,667	$	226,485	$	14,153	$	1,029
Interest expense	$	41,128	$	39,112	$	2,016	$	—
Income before income taxes	$	200,539	$	187,373	$	12,137	$	1,029
Total assets	$	2,505,984	$	2,360,156	$	145,828	$	—
Goodwill	$	182,145	$	182,145	$	—	$	—
Capital expenditures (including the effects of accruals)	$	197,684	$	189,671	$	8,013	$	—