Summary of Significant Accounting Policies (Tables)

6 Months Ended

Mar. 31, 2019

Accounting Policies [Abstract]

Schedule of Inter-Company Transactions

In addition, Spire Missouri’s other transactions with affiliates included

	Three Months Ended March 31,				Six Months Ended March 31,
	2019		2018		2019		2018
Purchases of natural gas from Spire Marketing	$	29.2	$	19.3	$	69.0	$	41.6
Sales of natural gas to Spire Marketing		—		0.2		1.4		0.3
Transportation services received from Spire NGL Inc.		0.2		0.2		0.5		0.5

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.

	March 31,		September 30,		March 31,
	2019		2018		2018
Spire	$	63.6	$	62.1	$	29.1
Spire Missouri		19.0		36.7		17.9
Spire Alabama		12.1		8.9		7.0