Recurring Fair Value Measurements (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Obligation to return cash		$ 0		$ 0		$ 0
Right to reclaim cash		12		12		16
Commodity Trading
Changes in Level 3 Commodity Derivatives [Roll Forward]
Balance at beginning of period		76	$ 12	56	$ (11)
Settlements	[1]	(73)	(19)	(92)	(26)
Gains recognized in earnings (b)	[2]	41	33	91	63
Net gains recognized as regulatory assets and liabilities (a)	[1]	28	12	18	12
Balance at end of period		230	92	230	92
Purchases/Issuances (a)	[1]	158	54	157	$ 54
Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative asset		204		204		53
Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability		99		99		35
Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability		103		103		71
Fair Value Measured on a Recurring Basis | Level 3
Changes in Level 3 Commodity Derivatives [Roll Forward]
Transfers level 3, net			$ 0	0
Fair Value Measured on a Recurring Basis | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross		365		365		107
Netting, asset	[3]	(163)		(163)		(54)
Derivative asset		202		202		53
Fair Value Measured on a Recurring Basis | Other Current Assets | Level 1
Derivatives, Fair Value [Line Items]
Derivative asset, gross		32		32		9
Fair Value Measured on a Recurring Basis | Other Current Assets | Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, gross		128		128		46
Fair Value Measured on a Recurring Basis | Other Current Assets | Level 3
Derivatives, Fair Value [Line Items]
Derivative asset, gross		205		205		52
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		221		221		71
Netting, asset	[3]	(160)		(160)		(53)
Derivative asset		61		61		18
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		144		144		30
Netting, asset	[3]	(3)		(3)		(1)
Derivative asset		141		141		29
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		6
Netting, asset	[3]	0		0		0
Derivative asset		0		0		6
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 1 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		32		32		9
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 1 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 1 | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 2 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		128		128		40
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 2 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 2 | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		6
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 3 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		61		61		22
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 3 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		144		144		30
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Level 3 | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross		154		154		75
Netting, asset	[3]	(81)		(81)		(42)
Derivative asset		73		73		33
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 1
Derivatives, Fair Value [Line Items]
Derivative asset, gross		26		26		6
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, gross		49		49		34
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 3
Derivatives, Fair Value [Line Items]
Derivative asset, gross		79		79		35
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Other Derivative Instruments | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		154		154		75
Netting, asset	[3]	(81)		(81)		(42)
Derivative asset		73		73		33
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Other Derivative Instruments | Level 1 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		26		26		6
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Other Derivative Instruments | Level 2 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		49		49		34
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Other Derivative Instruments | Level 3 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		79		79		35
Fair Value Measured on a Recurring Basis | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross		222		222		80
Netting, liability	[3]	(137)		(137)		(59)
Derivative liability		85		85		21
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Level 1
Derivatives, Fair Value [Line Items]
Derivative liability, gross		35		35		13
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Level 2
Derivatives, Fair Value [Line Items]
Derivative liability, gross		173		173		62
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Level 3
Derivatives, Fair Value [Line Items]
Derivative liability, gross		14		14		5
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		218		218		75
Netting, liability	[3]	(134)		(134)		(58)
Derivative liability		84		84		17
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		3		3		1
Netting, liability	[3]	(3)		(3)		(1)
Derivative liability		0		0		0
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		1		1		4
Netting, liability	[3]	0		0		0
Derivative liability		1		1		4
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 1 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		35		35		13
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 1 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 1 | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 2 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		172		172		58
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 2 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 2 | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		1		1		4
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 3 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		11		11		4
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 3 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		3		3		1
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Level 3 | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross		164		164		89
Netting, liability	[3]	(93)		(93)		(53)
Derivative liability		71		71		36
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 1
Derivatives, Fair Value [Line Items]
Derivative liability, gross		47		47		15
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 2
Derivatives, Fair Value [Line Items]
Derivative liability, gross		77		77		48
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 3
Derivatives, Fair Value [Line Items]
Derivative liability, gross		40		40		26
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Other Derivative Instruments | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		164		164		89
Netting, liability	[3]	(93)		(93)		(53)
Derivative liability		71		71		36
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Other Derivative Instruments | Level 1 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		47		47		15
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Other Derivative Instruments | Level 2 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		77		77		48
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Other Derivative Instruments | Level 3 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		40		40		26
Fair Value, Measurements, Nonrecurring | Other Current Assets | PPAs
Derivatives, Fair Value [Line Items]
Derivative asset	[4]	2		2		0
Fair Value, Measurements, Nonrecurring | Other Current Liabilities | PPAs
Derivatives, Fair Value [Line Items]
Derivative liability	[4]	14		14		14
Fair Value, Measurements, Nonrecurring | Other Noncurrent Liabilities | PPAs
Derivatives, Fair Value [Line Items]
Derivative liability	[4]	$ 32		$ 32		$ 35

[1] Relates primarily to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income.

[2] Relates to commodity trading and is subject to offsetting losses of derivative instruments categorized as levels 1 and 2 in the consolidated income statement.

[3] NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at June 30, 2022 and Dec. 31, 2021. At both June 30, 2022 and Dec. 31, 2021, derivative assets and liabilities include no obligations to return cash collateral. At June 30, 2022 and Dec. 31, 2021 derivative assets and liabilities include rights to reclaim cash collateral of $12 million and $16 million, respectively. The counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.(b)Amounts relate to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income.

[4] During 2006, Xcel Energy qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.