CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Operating Activities:
Net Income	$ 184.6	$ 214.2	$ 161.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	181.7	168.4	154.1
Deferred income taxes and investment tax credits	31.8	(28.7)	77.0
Changes in assets and liabilities:
Accounts receivable	2.7	(32.7)	(63.0)
Inventories	13.6	15.5	(23.5)
Regulatory assets and liabilities		191.0	5.6
Accounts payable	(6.4)	12.6	51.1
Delayed/advance customer billings, net	12.4	(12.8)	(40.0)
Taxes accrued	3.5	6.4	5.8
Other assets and liabilities	31.0	(121.2)	(45.8)
Other	(4.0)	43.9	5.4
Net cash provided by operating activities	450.9	456.6	288.3
Investing Activities:
Capital expenditures	(823.3)	(499.4)	(438.1)
Final settlement of 2016 acquisition of Spire EnergySouth (net of $2.0 cash acquired)			3.8
Other business acquisitions	(7.9)	(28.1)
Other	(7.1)	(4.2)	0.8
Net cash used in investing activities	(838.3)	(531.7)	(433.5)
Financing Activities:
Issuance of preferred stock	242.0
Issuance of long-term debt	230.0	75.0	420.0
Repayment of long-term debt	(184.1)	(105.0)	(393.8)
Issuance of short-term debt, net	189.6	76.3	78.6
Issuance of common stock	19.5	154.7	146.9
Dividends paid on common stock	(119.0)	(108.7)	(96.2)
Dividends paid on preferred stock	(3.4)
Other	(2.8)	(3.2)	(8.1)
Net cash provided by financing activities	371.8	89.1	147.4
Net (Decrease) Increase in Cash, Cash Equivalents, and Restricted Cash	(15.6)	14.0	2.2
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year	21.4	7.4	5.2
Cash, Cash Equivalents, and Restricted Cash at End of Year	5.8	21.4	7.4
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(102.4)	(95.1)	(85.5)
Income taxes	(2.7)	(1.5)	(1.3)
Spire Missouri
Operating Activities:
Net Income	115.0	129.3	113.0
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	111.5	102.8	93.1
Deferred income taxes and investment tax credits	13.2	(32.6)	47.5
Changes in assets and liabilities:
Accounts receivable	(0.3)	(2.0)	(20.5)
Inventories	29.0	8.4	(13.0)
Regulatory assets and liabilities	32.7	141.5	37.7
Accounts payable	(8.4)	(14.8)	16.8
Delayed/advance customer billings, net	13.9	(7.4)	(37.6)
Taxes accrued	4.4	(2.1)	5.0
Other assets and liabilities	(2.6)	(83.9)	(62.0)
Other	5.2	45.0	2.7
Net cash provided by operating activities	313.6	284.2	182.7
Investing Activities:
Capital expenditures	(356.9)	(295.8)	(282.2)
Other	1.3	4.8	1.1
Net cash used in investing activities	(355.6)	(291.0)	(281.1)
Financing Activities:
Issuance of first mortgage bonds	100.0		170.0
Repayment of short-term debt, net	(50.0)	(100.0)	(243.7)
Borrowings from Spire	41.1	142.3	203.0
Dividends paid on common stock	(48.5)	(36.0)	(28.7)
Other			(1.8)
Net cash provided by financing activities	42.6	6.3	98.8
Net (Decrease) Increase in Cash, Cash Equivalents, and Restricted Cash	0.6	(0.5)	0.4
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year	2.0	2.5	2.1
Cash, Cash Equivalents, and Restricted Cash at End of Year	2.6	2.0	2.5
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(48.7)	(45.6)	(38.6)
Spire Alabama
Operating Activities:
Net Income	60.3	1.3	58.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	56.2	53.2	49.9
Deferred income taxes and investment tax credits	20.5	81.6	35.8
Changes in assets and liabilities:
Accounts receivable	0.8	(16.2)	(10.0)
Inventories	(1.2)	(1.2)	0.1
Regulatory assets and liabilities	(28.2)	40.7	(18.3)
Accounts payable	4.5	4.7	8.8
Delayed/advance customer billings, net	(2.5)	(5.5)	(2.5)
Taxes accrued	(0.9)	4.9	1.8
Other assets and liabilities	34.8	(16.7)	(38.0)
Other	(3.2)	(0.7)	(1.2)
Net cash provided by operating activities	141.1	146.1	84.5
Investing Activities:
Capital expenditures	(174.5)	(131.7)	(113.9)
Other	(3.3)	(1.6)	(0.4)
Net cash used in investing activities	(177.8)	(133.3)	(114.3)
Financing Activities:
Repayment of short-term debt, net	0.0	0.0	(82.0)
Issuance of long-term debt	90.0	75.0	0.0
(Repayments of) borrowings from Spire	(13.8)	(27.4)	169.9
Return of capital to Spire	(20.0)	(30.0)	(31.0)
Dividends paid on common stock	(19.0)	(30.0)	(27.0)
Other	(0.5)	(0.5)	0.0
Net cash provided by financing activities	36.7	(12.9)	29.9
Net (Decrease) Increase in Cash, Cash Equivalents, and Restricted Cash	0.0	(0.1)	0.1
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year	0.0	0.1	0.0
Cash, Cash Equivalents, and Restricted Cash at End of Year	0.0	0.0	0.1
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(19.2)	(15.1)	(12.8)
Income taxes	$ 0.0	$ 0.0	$ 0.0