CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities:
Net Income	$ 200.6	$ 221.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	96.7	89.1
Deferred income taxes and investment tax credits	42.8	45.5
Changes in assets and liabilities:
Accounts receivable	(64.4)	(194.3)
Inventories	69.5	83.9
Regulatory assets and liabilities	74.7	105.9
Accounts payable	(50.5)	33.6
Delayed/advance customer billings, net	(33.6)	(53.2)
Taxes accrued	(14.1)	(12.9)
Other assets and liabilities	0.1	(20.6)
Other	(0.1)	(1.4)
Net cash provided by operating activities	321.7	297.5
Investing Activities:
Capital expenditures	(346.1)	(376.8)
Business acquisitions	0.0	(7.9)
Other	1.5	(1.9)
Net cash used in investing activities	(344.6)	(386.6)
Financing Activities:
Issuance of long-term debt	510.0	190.0
Repayment of long-term debt	(140.0)	(9.1)
Repayment of short-term debt, net	(182.6)	(41.6)
Issuance of common stock	15.2	1.0
Dividends paid on common stock	(63.8)	(58.8)
Dividends paid on preferred stock	(7.4)	0.0
Other	(5.9)	(2.7)
Net cash provided by financing activities	125.5	78.8
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	102.6	(10.3)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	5.8	21.4
Cash and Cash Equivalents at End of Period	108.4	11.1
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(46.7)	(49.0)
Income taxes	(1.7)	(2.0)
Spire Missouri
Operating Activities:
Net Income	122.5	131.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	58.3	55.0
Deferred income taxes and investment tax credits	16.4	19.1
Changes in assets and liabilities:
Accounts receivable	(67.6)	(123.5)
Inventories	39.3	74.9
Regulatory assets and liabilities	59.8	107.3
Accounts payable	6.8	11.1
Delayed/advance customer billings, net	(27.9)	(46.4)
Taxes accrued	(9.8)	(4.8)
Other assets and liabilities	(1.9)	(14.4)
Other	0.3	2.6
Net cash provided by operating activities	196.2	212.1
Investing Activities:
Capital expenditures	(183.2)	(167.1)
Other	0.3	0.8
Net cash used in investing activities	(182.9)	(166.3)
Financing Activities:
Issuance of long-term debt	275.0	100.0
Repayment of long-term debt	(100.0)	0.0
Issuance of short-term debt, net	185.1	0.0
Repayments to Spire, net	(346.8)	(112.4)
Dividends paid on common stock	(22.6)	(28.5)
Other	(1.5)	0.0
Net cash provided by financing activities	(10.8)	(40.9)
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	2.5	4.9
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2.6	2.0
Cash and Cash Equivalents at End of Period	5.1	6.9
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(21.6)	(23.8)
Income taxes	0.0	0.0
Spire Alabama
Operating Activities:
Net Income	71.0	67.0
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	28.9	27.3
Deferred income taxes and investment tax credits	23.9	22.5
Changes in assets and liabilities:
Accounts receivable	(27.9)	(33.5)
Inventories	18.3	3.7
Regulatory assets and liabilities	13.7	0.6
Accounts payable	(10.8)	4.0
Delayed/advance customer billings, net	(5.3)	(7.8)
Taxes accrued	(4.4)	(7.1)
Other assets and liabilities	(7.8)	8.9
Other	(2.5)	(2.4)
Net cash provided by operating activities	97.1	83.2
Investing Activities:
Capital expenditures	(75.8)	(65.7)
Other	(3.0)	(1.1)
Net cash used in investing activities	(78.8)	(66.8)
Financing Activities:
Issuance of long-term debt	100.0	90.0
Repayment of long-term debt	(40.0)	0.0
Issuance of short-term debt, net	50.0	0.0
Return of capital to Spire	(20.0)	(20.0)
Repayments to Spire, net	(95.7)	(68.8)
Dividends paid on common stock	(12.0)	(17.0)
Other	(0.5)	(0.5)
Net cash provided by financing activities	(18.2)	(16.3)
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	0.1	0.1
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	0.0	0.0
Cash and Cash Equivalents at End of Period	0.1	0.1
Supplemental disclosure of cash paid for:
Interest, net of amounts capitalized	(9.5)	(8.7)
Income taxes	$ 0.0	$ 0.0