Commitments And Contingencies (Narrative) (Details) $ in Millions	12 Months Ended
Sep. 30, 2022 USD ($)
Site Contingency [Line Items]
Estimate minimum liability for environmental remediation	$ 3.6
Rate recovery period	1 year
Project Costs	$ 55.8
Future purchase obligation first year	458.2
Future purchase obligation second year	98.6
Future purchase obligation third year	135.6
Future purchase obligation fourth year	150.7
Future purchase obligation fifth year	142.1
Future purchase obligation thereafter	1,001.0
Pipeline And Storage, Gathering And Utility Segments [Member]
Site Contingency [Line Items]
Contract commitments first year	68.9
Contract commitments second year	8.5
Contract commitments third year	8.1
Contract commitments fourth year	6.9
Contract commitments fifth year	5.8
Contract commitments thereafter	5.8
Exploration And Production [Member]
Site Contingency [Line Items]
Contract commitments first year	282.5
Contract commitments second year	180.4
Contract commitments third year	153.8
Contract commitments fourth year	$ 43.8

Project costs included within Property, Plant and Equipment and Deferred Charges on the Consolidated Balance Sheet

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