Segment Information (Tables)

9 Months Ended

Jun. 30, 2019

Segment Reporting [Abstract]

Schedule of Segment Information

				Reportable Segments
Three Months Ended June 30, 2019	Total			Gas Utility			Electric Utility
Revenues	$	163,893		$	144,441		$	19,452
Cost of sales	$	61,021		$	51,626		$	9,395
Depreciation	$	23,141		$	21,612		$	1,529
Operating income	$	20,325		$	18,592		$	1,733
Pension and other postretirement plans non-service income	$	440		$	387		$	53
Interest expense	$	(12,325	)	$	(11,522	)	$	(803	)
Income before income taxes	$	8,440		$	7,457		$	983
Capital expenditures (including the effects of accruals)	$	84,451		$	79,272		$	5,179

				Reportable Segments
Three Months Ended June 30, 2018	Total			Gas Utility			Electric Utility
Revenues	$	159,934		$	138,597		$	21,337
Cost of sales	$	72,537		$	60,837		$	11,700
Depreciation	$	21,414		$	20,011		$	1,403
Operating income (a)	$	4,483		$	3,126		$	1,357
Pension and other postretirement plans non-service expense (a)	$	(569	)	$	(498	)	$	(71	)
Interest expense	$	(10,003	)	$	(9,829	)	$	(174	)
(Loss) income before income taxes	$	(6,089	)	$	(7,201	)	$	1,112
Capital expenditures (including the effects of accruals)	$	79,704		$	76,546		$	3,158

				Reportable Segments
Nine Months Ended June 30, 2019	Total			Gas Utility			Electric Utility
Revenues	$	916,210		$	842,998		$	73,212
Cost of sales	$	438,516		$	398,910		$	39,606
Depreciation	$	67,956		$	63,554		$	4,402
Operating income	$	217,265		$	208,756		$	8,509
Pension and other postretirement plans non-service income	$	1,247		$	1,094		$	153
Interest expense	$	(36,294	)	$	(34,362	)	$	(1,932	)
Income before income taxes	$	182,218		$	175,488		$	6,730
Capital expenditures (including the effects of accruals)	$	232,569		$	221,112		$	11,457
As of June 30, 2019
Total assets	$	3,375,622		$	3,191,316		$	184,306
Goodwill	$	182,145		$	182,145		$	—

				Reportable Segments
Nine Months Ended June 30, 2018	Total			Gas Utility			Electric Utility
Revenues	$	966,300		$	894,535		$	71,765
Cost of sales	$	481,613		$	440,726		$	40,887
Depreciation	$	62,926		$	58,787		$	4,139
Operating income (a)	$	237,124		$	232,049		$	5,075
Pension and other postretirement plans non-service expense (a)	$	(1,788	)	$	(1,565	)	$	(223	)
Interest expense	$	(32,033	)	$	(31,221	)	$	(812	)
Income before income taxes	$	203,303		$	199,263		$	4,040
Capital expenditures (including the effects of accruals)	$	206,492		$	196,751		$	9,741
As of June 30, 2018
Total assets	$	3,194,025		$	3,008,441		$	185,584
Goodwill	$	182,145		$	182,145		$	—