Summary of Significant Accounting Policies (Tables)

9 Months Ended

Jun. 30, 2020

Accounting Policies [Abstract]

Schedule of Inter-Company Transactions

In addition, Spire Missouri’s other transactions with affiliates are presented in the table below

	Three Months Ended June 30,				Nine Months Ended June 30,
	2020		2019		2020		2019
Purchases of natural gas from Spire Marketing Inc.	$	10.9	$	12.3	$	43.7	$	81.3
Transportation services received from Spire STL Pipeline LLC		8.0		—		19.8		—
Sales of natural gas to Spire Marketing Inc.		—		0.2		—		1.6
Transportation services received from Spire NGL Inc.		0.3		0.3		0.8		0.8

Schedule of Capital Expenditures Excluded from Statement of Cash Flow

Accrued capital expenditures, shown in the following table, are excluded from capital expenditures in the statements of cash flows until paid.

	June 30,		September 30,		June 30,
	2020		2019		2019
Spire	$	54.4	$	80.6	$	60.2
Spire Missouri		28.9		40.1		26.3
Spire Alabama		14.4		11.9		9.0