Derivative, Credit Risk Exposure, Percentage

No definition available.

Name:	psd_DerivativeCreditRiskExposurePercentage
Namespace Prefix:	psd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Hedging strategy number of years extended

+ References

No definition available.

+ Details

Name:	psd_Hedgingstrategynumberofyearsextended
Namespace Prefix:	psd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959

+ Details

Name:	us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix:	us-gaap_
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

No definition available.

+ Details

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

- Definition

Nominal number of units used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

+ Details

Name:	us-gaap_DerivativeNonmonetaryNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	srt_ConsolidatedEntitiesAxis=srt_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=psd_ElectricGenerationFuelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_ExternalCreditRatingByGroupingAxis=us-gaap_ExternalCreditRatingNonInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ContingentConsiderationByTypeAxis=psd_CreditRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=psd_NaturalGasPortfolioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Accounting for Derivative Instruments and Hedging Activities Narrative (Details) MMBTU in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($) MMBTU	Dec. 31, 2019 MMBTU
Subsidiaries [Member]
Derivative [Line Items]
Hedging strategy number of years extended	3 years
Electric Generation Fuel [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount \| MMBTU	234.0	229.3
External Credit Rating, Investment Grade [Member]
Derivative [Line Items]
Derivative, Credit Risk Exposure, Percentage	98.00%
External Credit Rating, Non Investment Grade [Member]
Derivative [Line Items]
Derivative, Credit Risk Exposure, Percentage	2.10%
Credit Rating [Member]
Derivative [Line Items]
Posted Collateral	$ 9.0
Credit Rating [Member] \| Natural Gas Portfolio [Member]
Derivative [Line Items]
Posted Collateral	$ 6.3