Fair Value of Financial Assets and Liabilities - Consideration of Credit Risk and Concentrations (Details) $ in Millions	Sep. 30, 2026 USD ($) Counterparty	Dec. 31, 2025 USD ($)
Derivative [Line Items]
Derivative, Gross Liability with Cross Default Position, Aggregate Fair Value \| $	$ 4	$ 7
Credit Concentration Risk
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure	9
Credit Concentration Risk \| Municipal or Cooperative Entities or Other Utilities [Member]
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure	8
Credit Concentration Risk \| External Credit Rating, Investment Grade [Member]
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure	1
Wholesale, trading and non-trading commodity credit exposure for the most significant counterparties \| $	$ 2
Percentage of wholesale, trading and non-trading commodity credit exposure for the most significant counterparties (in hundredths)	4.00%
Credit Concentration Risk \| Internal Investment Grade
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure	8
Wholesale, trading and non-trading commodity credit exposure for the most significant counterparties \| $	$ 26
Percentage of wholesale, trading and non-trading commodity credit exposure for the most significant counterparties (in hundredths)	71.00%

Derivative, Gross Liability with Cross Default Position, Aggregate Fair Value

No definition available.

Name:	psco_DerivativeGrossLiabilityWithCrossDefaultPositionAggregateFairValue
Namespace Prefix:	psco_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of the entity's most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure.

+ References

No definition available.

+ Details

Name:	psco_Numberofmostsignificantcounterpartiesforwholesaletradingandnontradingcommodityactivitieswithcreditexposure
Namespace Prefix:	psco_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of wholesale, trading and non-trading commodity credit exposure for the entity's most significant counterparties.

+ References

No definition available.

+ Details

Name:	psco_PercentageOfWholesaleTradingAndNonTradingCommodityCreditExposureForMostSignificantCounterparties
Namespace Prefix:	psco_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Wholesale, trading and non-trading commodity credit exposure for the entity's most significant counterparties.

+ References

No definition available.

+ Details

Name:	psco_WholesaleTradingAndNonTradingCommodityCreditExposureForMostSignificantCounterparties
Namespace Prefix:	psco_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A

+ Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CreditConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByIndustryOfCounterpartyTypeAxis=psco_MunicipalorCooperativeEntitiesorOtherUtilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	psco_CreditQualityIndicatorAxis=us-gaap_ExternalCreditRatingInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	psco_CreditQualityIndicatorAxis=us-gaap_InternalInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: