Commitments and Contingencies, Capital Commitments (Details)	12 Months Ended
Dec. 31, 2016 MW
Capital Commitments \| Rush Creek Wind Farm [Member]
Capital Commitments [Abstract]
Public Utilities, Facility Generating Capacity	600

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No definition available.

Name:	psco_CapitalCommitmentsAbstract
Namespace Prefix:	psco_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration