Commitments and Contingencies, Capital Commitments (Details)	12 Months Ended
Dec. 31, 2013 Project
Capital Commitments [Abstract]
Number of major projects with capital commitments	2
Capital Commitments \| Clean Air Clean Jobs Act
Capital Commitments [Abstract]
Percentage reduction in annual emissions of NOx from 2008 levels, low end of range (in hundredths)	70.00%
Percentage reduction in annual emissions of NOx from 2008 levels, high end of range (in hundredths)	80.00%

The high end of the range of the targeted reduction in annual emissions of NOx from 2008 by 2017 levels from the coal fired generation identified in the plan for the Clean Air Clean Jobs Act (CACJA).

No definition available.

Name:	psco_PercentageReductionInAnnualEmissionsOfNoxFromPreviousLevelsHighEndOfRange
Namespace Prefix:	psco_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration