Variable Interest Entities (Details) - MW	Mar. 31, 2020	Dec. 31, 2019
Independent Power Producing Entities
Purchased Power Agreements [Abstract]
Generating capacity under long term purchased power agreements (in MW)	1,442	1,442

Generating capacity under long-term purchased power agreements.

No definition available.

Name:	psco_GeneratingCapacityUnderLongTermPurchasedPowerAgreements
Namespace Prefix:	psco_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	instant