CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating revenues	$ 875,563	$ 877,782
Purchased gas cost	296,868	342,165
Operation and maintenance expense	152,245	138,600
Depreciation and amortization expense	105,062	96,065
Taxes, other than income	68,607	64,488
Operating income	252,781	236,464
Other non-operating income (expense)	4,887	(7,723)
Interest charges	27,229	27,849
Income before income taxes	230,439	200,892
Income tax expense	51,766	43,246
Net income	$ 178,673	$ 157,646
Net income per share - Basic (USD per share)	$ 1.47	$ 1.38
Net income per share - Diluted (USD per share)	1.47	1.38
Cash dividends per share (USD per share)	$ 0.575	$ 0.525
Basic weighted average shares outstanding (in shares)	121,113	113,800
Diluted weighted average shares outstanding (in shares)	121,359	113,832
Other comprehensive income (loss), net of tax
Net unrealized holding losses on available-for-sale securities, net of tax of $0 and $0	$ (1)	$ 0
Cash flow hedges:
Amortization and unrealized loss on interest rate agreements, net of tax of $311 and $(6,580)	1,053	(22,258)
Total other comprehensive income (loss)	1,052	(22,258)
Total comprehensive income	179,725	135,388
Distribution segment
Operating revenues	827,840	838,181
Pipeline and storage segment
Operating revenues	47,723	39,601
Intersegment eliminations
Operating revenues	(101,117)	(95,523)
Purchased gas cost	(100,789)	(95,209)
Operation and maintenance expense	(328)	(314)
Depreciation and amortization expense	0	0
Taxes, other than income	0	0
Operating income	0	0
Other non-operating income (expense)	0	0
Interest charges	0	0
Income before income taxes	0	0
Income tax expense	0	0
Net income	0	0
Intersegment eliminations | Distribution segment
Operating revenues	(664)	654
Intersegment eliminations | Pipeline and storage segment
Operating revenues	(100,453)	94,869
Operating Segments | Distribution segment
Operating revenues	828,504	838,835
Purchased gas cost	397,558	437,732
Operation and maintenance expense	114,352	105,767
Depreciation and amortization expense	76,074	69,709
Taxes, other than income	60,243	56,190
Operating income	180,277	169,437
Other non-operating income (expense)	1,954	(6,477)
Interest charges	16,362	18,210
Income before income taxes	165,869	144,750
Income tax expense	36,112	30,365
Net income	129,757	114,385
Operating Segments | Pipeline and storage segment
Operating revenues	148,176	134,470
Purchased gas cost	99	(358)
Operation and maintenance expense	38,221	33,147
Depreciation and amortization expense	28,988	26,356
Taxes, other than income	8,364	8,298
Operating income	72,504	67,027
Other non-operating income (expense)	2,933	(1,246)
Interest charges	10,867	9,639
Income before income taxes	64,570	56,142
Income tax expense	15,654	12,881
Net income	$ 48,916	$ 43,261