Commitments and Contingencies, Environmental Contingencies (Details)	9 Months Ended
Sep. 30, 2016
Implementation of the National Ambient Air Quality Standard for Sulfur Dioxide
Environmental Requirements [Abstract]
Number of phases under a consent decree which the EPA is requiring states to evaluate areas for attainment	3

Number of phases under a consent decree which the EPA is requiring states to evaluate areas for attainment

No definition available.

Name:	psco_NumberofphasesunderaconsentdecreewhichtheEPAisrequiringstatestoevaluateareasforattainment
Namespace Prefix:	psco_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration