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Regulatory Matters: Rate Review (Details) $ in Millions	Oct. 08, 2021 USD ($) mi	Oct. 05, 2021 USD ($) mi	Jul. 06, 2021	Jun. 01, 2021 USD ($) mi	Mar. 01, 2021 USD ($) mi	Sep. 11, 2020
Settlement agreement reached with CPUC Staff and various intervenors, subject to the review and approval by an Administrative Law Judge and the CPUC. | Colorado Public Utilities Commission (CPUC) | Colorado Gas | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments | mi		7,000
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 6.5
Public Utilities, Approved Equity Capital Structure, Percentage		50.30%
Public Utilities, Approved Debt Capital Structure, Percentage		49.70%
Public Utilities, Requested Return on Equity, Percentage		9.20%
Rate Review Filed with the Regulatory Agency | Colorado Public Utilities Commission (CPUC) | Colorado Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Term Extension of System Safety and Integrity Rider						5 years
Rate Review Filed with the Regulatory Agency | Iowa Utilities Board (IUB) | Iowa Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments | mi				5,000
Public Utilities, Requested Rate Increase (Decrease), Amount				$ 8.3
Public Utilities, Requested Equity Capital Structure, Percentage				50.00%
Public Utilities, Requested Debt Capital Structure, Percentage				50.00%
Public Utilities, Requested Return on Equity, Percentage				10.15%
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates Requested				$ 2.2
Public Utilities, Number of Days After Filing a Rate Review the Interim Rates May Be Implemented				10 days
Rate Review Approved by Regulatory Agency | Colorado Public Utilities Commission (CPUC) | Colorado Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities, Term Extension of System Safety and Integrity Rider			3 years
Rate Review Approved by Regulatory Agency | Nebraska Publc Service Commission (NPSC) | Nebraska Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Return on Equity, Percentage					9.50%
Public Utilities, Approved Equity Capital Structure, Percentage					50.00%
Public Utilities, Approved Debt Capital Structure, Percentage					50.00%
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates Requested					$ 4.6
Public Utilities, Approved Rate Increase (Decrease), Amount					$ 6.5
Global Settlement agreement with KCC Staff and various intervenors for a general rate increase and renewal of its safety and integrity rider. | Kansas Corporation Commission (KCC) | Kansas Gas | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments | mi	4,600
Public Utilities, Term Extension of System Safety and Integrity Rider	5 years
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates Requested	$ 6.6
Approval Recevied from Regulatory Agency | Nebraska Publc Service Commission (NPSC) | Nebraska Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments | mi					13,000
Public Utilities, Term Extension of System Safety and Integrity Rider					5 years

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