CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
ASSETS
Utility Plant	$ 6,860.2	$ 6,766.3	$ 6,256.1
Less: Accumulated depreciation and amortization	2,113.3	2,086.2	1,823.8
Net Utility Plant	4,746.9	4,680.1	4,432.3
Non-utility Property (net of accumulated depreciation and amortization of $22.2, $19.0 and $13.9 at December 31, 2020, September 30, 2020, and December 31, 2019, respectively)	448.7	432.3	518.7
Other Investments	74.8	71.7	74.7
Total Other Property and Investments	523.5	504.0	593.4
Current Assets:
Cash and cash equivalents	3.5	4.1	21.5
Accounts receivable:
Utility	281.5	131.8	282.0
Other	170.4	146.4	195.6
Allowance for credit losses	(28.9)	(24.9)	(26.3)
Delayed customer billings	13.6	10.0	6.6
Inventories:
Natural gas	145.9	154.3	149.1
Propane gas	10.7	10.7	10.7
Materials and supplies	27.9	26.5	25.8
Regulatory assets	70.5	69.5	67.9
Prepayments	30.8	29.2	30.8
Other	44.1	33.0	12.7
Total Current Assets	770.0	590.6	776.4
Deferred Charges and Other Assets:
Goodwill	1,171.6	1,171.6	1,171.6
Regulatory assets	1,079.2	1,069.4	750.5
Other	224.4	225.5	236.8
Total Deferred Charges and Other Assets	2,475.2	2,466.5	2,158.9
Total Assets	8,515.6	8,241.2	7,961.0
Capitalization:
Preferred stock ($25.00 par value per share; 10.0 million depositary shares authorized, issued and outstanding at December 31, 2020, September 30, 2020, and December 31, 2019)	242.0	242.0	242.0
Common stock (par value $1.00 per share; 70.0 million shares authorized; 51.7 million, 51.6 million, and 51.1 million shares issued and outstanding at December 31, 2020, September 30, 2020, and December 31, 2019, respectively)	51.7	51.6	51.1
Paid-in capital and common stock	1,550.0	1,549.2	1,506.7
Retained earnings	771.2	720.7	803.1
Accumulated other comprehensive loss	(28.1)	(41.2)	(16.9)
Total Shareholders' Equity	2,586.8	2,522.3	2,586.0
Temporary equity	5.3	3.4	4.1
Long-term debt (less current portion)	2,517.6	2,423.7	2,484.4
Total Capitalization	5,109.7	4,949.4	5,074.5
Current Liabilities:
Current portion of long-term debt	110.8	60.4	45.3
Notes payable	696.1	648.0	518.9
Accounts payable	260.8	243.3	307.9
Advance customer billings	43.2	45.3	31.4
Wages and compensation accrued	26.7	46.3	35.4
Customer deposits	30.9	30.6	36.5
Taxes accrued	41.2	71.4	43.8
Regulatory liabilities	95.5	113.0	50.0
Other	241.5	190.9	183.3
Total Current Liabilities	1,546.7	1,449.2	1,252.5
Deferred Credits and Other Liabilities:
Deferred income taxes	541.9	511.4	475.3
Pension and postretirement benefit costs	289.2	309.0	260.7
Asset retirement obligations	545.6	540.1	340.9
Regulatory liabilities	357.3	343.7	417.8
Other	125.2	138.4	139.3
Total Deferred Credits and Other Liabilities	1,859.2	1,842.6	1,634.0
Commitments and Contingencies (Note 10)
Total Capitalization and Liabilities	8,515.6	8,241.2	7,961.0
Spire Missouri
ASSETS
Utility Plant	4,012.8	3,931.2	3,718.9
Less: Accumulated depreciation and amortization	851.5	825.7	780.1
Net Utility Plant	3,161.3	3,105.5	2,938.8
Other Investments	59.0	56.7	56.8
Current Assets:
Cash and cash equivalents	0.0	0.0	9.3
Accounts receivable:
Utility	195.4	92.5	193.8
Associated companies	2.3	2.7	4.8
Other	23.6	34.1	23.7
Allowance for credit losses	(21.4)	(18.1)	(17.9)
Delayed customer billings	5.1	2.4	6.6
Inventories:
Natural gas	88.3	95.1	92.7
Propane gas	10.7	10.7	10.7
Materials and supplies	16.1	15.6	15.2
Regulatory assets	32.1	32.1	29.4
Prepayments	20.9	20.7	17.8
Total Current Assets	373.1	287.8	386.1
Deferred Charges and Other Assets:
Goodwill	210.2	210.2	210.2
Regulatory assets	550.4	548.7	491.1
Other	96.1	96.0	88.1
Total Deferred Charges and Other Assets	856.7	854.9	789.4
Total Assets	4,450.1	4,304.9	4,171.1
Capitalization:
Paid-in capital and common stock	765.1	765.1	765.1
Retained earnings	729.5	672.9	613.3
Accumulated other comprehensive loss	(2.8)	(2.9)	(2.3)
Total Shareholders' Equity	1,491.8	1,435.1	1,376.1
Long-term debt (less current portion)	1,092.2	1,092.0	1,098.6
Total Capitalization	2,584.0	2,527.1	2,474.7
Current Liabilities:
Notes payable – associated companies	393.7	301.2	288.1
Accounts payable	82.6	66.7	76.3
Accounts payable – associated companies	7.1	9.3	11.2
Advance customer billings	29.8	32.7	20.7
Wages and compensation accrued	19.5	33.3	25.0
Customer deposits	9.0	9.3	13.6
Taxes accrued	13.4	39.1	14.6
Regulatory liabilities	83.4	103.2	42.4
Other	82.6	39.9	65.7
Total Current Liabilities	721.1	634.7	557.6
Deferred Credits and Other Liabilities:
Deferred income taxes	449.4	434.7	376.2
Pension and postretirement benefit costs	198.7	217.2	189.3
Asset retirement obligations	155.0	153.4	175.3
Regulatory liabilities	288.2	274.8	345.5
Other	53.7	63.0	52.5
Total Deferred Credits and Other Liabilities	1,145.0	1,143.1	1,138.8
Commitments and Contingencies (Note 10)
Total Capitalization and Liabilities	4,450.1	4,304.9	4,171.1
Spire Alabama
ASSETS
Utility Plant	2,487.4	2,469.9	2,174.1
Less: Accumulated depreciation and amortization	1,122.8	1,117.0	894.2
Net Utility Plant	1,364.6	1,352.9	1,279.9
Accounts receivable:
Utility	69.6	31.4	71.6
Associated companies	0.7	0.6	0.2
Other	6.1	5.8	8.7
Allowance for credit losses	(6.2)	(5.5)	(7.4)
Delayed customer billings	8.5	7.5	0.0
Inventories:
Natural gas	23.8	22.5	30.6
Materials and supplies	9.2	8.4	8.1
Regulatory assets	22.7	20.4	24.4
Prepayments	5.5	4.3	6.6
Other	0.1	0.2	0.4
Total Current Assets	140.0	95.6	143.2
Deferred Charges and Other Assets:
Regulatory assets	498.2	489.9	230.2
Deferred income taxes	54.5	59.3	76.8
Other	53.5	53.7	62.5
Total Deferred Charges and Other Assets	606.2	602.9	369.5
Total Assets	2,110.8	2,051.4	1,792.6
Capitalization:
Paid-in capital and common stock	339.9	350.9	370.9
Retained earnings	509.0	500.8	466.3
Total Shareholders' Equity	848.9	851.7	837.2
Long-term debt (less current portion)	571.0	471.8	471.7
Total Capitalization	1,419.9	1,323.5	1,308.9
Current Liabilities:
Current portion of long-term debt	50.0	0.0	40.0
Notes payable – associated companies	27.0	121.3	67.1
Accounts payable	40.0	43.7	51.9
Accounts payable – associated companies	5.3	4.2	3.2
Advance customer billings	12.5	11.5	10.0
Wages and compensation accrued	4.2	8.0	6.5
Customer deposits	19.2	18.7	20.2
Taxes accrued	24.7	28.0	26.1
Regulatory liabilities	6.9	3.9	2.4
Other	22.5	11.8	13.2
Total Current Liabilities	212.3	251.1	240.6
Deferred Credits and Other Liabilities:
Pension and postretirement benefit costs	73.8	74.9	58.7
Asset retirement obligations	378.0	374.3	150.2
Regulatory liabilities	18.4	18.5	22.3
Other	8.4	9.1	11.9
Total Deferred Credits and Other Liabilities	478.6	476.8	243.1
Commitments and Contingencies (Note 10)
Total Capitalization and Liabilities	$ 2,110.8	$ 2,051.4	$ 1,792.6