The amount of expenses incurred in the period for information technology and data processing products and services.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.6)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

+ Details

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Namespace Prefix:	xel_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

For technology service agreements having initial or remaining terms in excess of one year, required payments due after the fifth year of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	xel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For technology service agreements having initial or remaining terms in excess of one year, required payments due within one year of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	xel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For technology service agreements having initial or remaining terms in excess of one year, required payments due within the fourth year of the balance sheet date.

+ References

No definition available.

+ Details

Name:	xel_LongTermPurchaseCommitmentTechnologyAgreementFutureMinimumPaymentsDueInFourYears
Namespace Prefix:	xel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For technology service agreements having initial or remaining terms in excess of one year, required payments due within the third year of the balance sheet date.

+ References

No definition available.

+ Details

Name:	xel_LongTermPurchaseCommitmentTechnologyAgreementFutureMinimumPaymentsDueInThreeYears
Namespace Prefix:	xel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For technology service agreements having initial or remaining terms in excess of one year, required payments due within the second year of the balance sheet date.

+ References

No definition available.

+ Details

Name:	xel_LongTermPurchaseCommitmentTechnologyAgreementFutureMinimumPaymentsDueInTwoYears
Namespace Prefix:	xel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percent of contract value to be paid if contract is cancelled by entity.

+ References

No definition available.

+ Details

Name:	xel_PercentOfContractValueToBePaidIfContractIsTerminated
Namespace Prefix:	xel_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

+ Details

Name:	xel_TechnologyAgreementsAbstract
Namespace Prefix:	xel_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

For technology service agreements having initial or remaining terms in excess of one year, required payments due within the fourth year of the balance sheet date.

+ References

No definition available.

+ Details

Name:	xel_Xel_LongTermPurchaseCommitmentTechnologyAgreementFutureMinimumPaymentsDueInFiveYears
Namespace Prefix:	xel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=xel_AccentureAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=xel_CognizantAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Technology Agreements (Details) - USD ($) $ in Millions	12 Months Ended
Technology Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
IBM Agreement [Member]
Technology Agreements [Abstract]
Percent of contract value to be paid if contract is terminated (in hundredths)	50.00%
Technology Agreements, Minimum Payments Due [Abstract]
2020	$ 15
2021	15
2022	6
2023	0
2024	0
Thereafter	0
Information Technology and Data Processing	46	$ 81	$ 98
Accenture Agreement [Member]
Technology Agreements, Minimum Payments Due [Abstract]
2020	11
2021	0
2022	0
2023	0
2024	0
Thereafter	0
Information Technology and Data Processing	52	$ 46	$ 16
Cognizant Agreement [Member]
Technology Agreements, Minimum Payments Due [Abstract]
2020	9
2021	7
2022	3
2023	0
2024	0
Thereafter	0
Information Technology and Data Processing	$ 3