Payment of reverse termination fee

No definition available.

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- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-3

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- Definition

Amount classified as deferred revenue attributable to disposal group held for sale or disposed of.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
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-Name Accounting Standards Codification
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-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482130/360-10-45-14

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5C
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483499/205-20-50-5C

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 205
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-Name Accounting Standards Codification
-Section 50
-Paragraph 5B
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483499/205-20-50-5B

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483475/205-20-45-11

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- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

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- Definition

The cash inflow from the sale of formerly productive land held for sale, anything permanently fixed to it, including buildings, structures on it, and so forth.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

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Subsequent Events - Additional Information (Details) - USD ($) $ in Millions		1 Months Ended		9 Months Ended
	Apr. 21, 2026	Jun. 30, 2026	Apr. 30, 2026	Jun. 30, 2026	Jun. 30, 2025
Subsequent Event [Line Items]
Cash proceeds from sale of business				$ 819.9	$ 0.0
Spire Marketing [Member] \| Discontinued Operations, Held-for-Sale [Member]
Subsequent Event [Line Items]
Cash proceeds from sale of business			$ 212.0
Spire Storage [Member] \| Discontinued Operations, Held-for-Sale [Member]
Subsequent Event [Line Items]
Cash proceeds from sale of business		$ 607.0
Total expected consideration from transaction		657.0		657.0
Deferred payment expected to be received in fiscal 2027		$ 50.0		$ 50.0
Spire Mississippi [Member] \| Asset Held for Sale (Continuing Operations) [Member]
Subsequent Event [Line Items]
Cash purchase price	$ 75.0
Reverse termination fee	$ 7.5