v3.25.2
Recurring Fair Value Measurements (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Derivatives, Fair Value [Line Items]          
Derivative liability $ 27   $ 27   $ 31
Derivative Liability, Noncurrent 67   67   77
Obligation to return cash 0   0   0
Right to reclaim cash 3   3   1
Changes in Level 3 Commodity Derivatives [Roll Forward]          
Miscellaneous investments 55   55   54
Commodity Trading          
Changes in Level 3 Commodity Derivatives [Roll Forward]          
Balance at beginning of period 15 $ 39 32 $ 51  
Settlements (13) (27) (22) [1] (42) [1]  
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings (6) 3 (8) [2] 3 [2]  
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liability Net Losses Gains Recognized As Regulatory Assets And Liabilities 0 6 (6) [1] 9 [1]  
Balance at end of period 58 93 58 93  
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Purchases 62 $ 72 62 [1] $ 72 [1]  
Fair Value Measured on a Recurring Basis          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 91   91   60
Netting, asset [3] (22)   (22)   (24)
Derivative Asset, Noncurrent 53   53   67
Derivative liability, gross 43   43   48
Netting, liability [3] (22)   (22)   (23)
Derivative liability 21   21   25
Derivative Liability, Noncurrent 54   54   61
Changes in Level 3 Commodity Derivatives [Roll Forward]          
Derivative Asset, Current 69   69   36
Fair Value Measured on a Recurring Basis | Level 1          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 5   5   5
Derivative liability, gross 6   6   6
Fair Value Measured on a Recurring Basis | Level 2          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 21   21   24
Derivative liability, gross 29   29   36
Fair Value Measured on a Recurring Basis | Level 3          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 65   65   31
Derivative liability, gross 8   8   6
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Commodity Trading          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 30   30   33
Netting, asset [3]         (22)
Derivative Asset, Noncurrent 53   53   67
Derivative liability, gross 40   40   46
Netting, liability [3] (20)   (20)   (22)
Derivative liability 20   20   24
Derivative Liability, Noncurrent 54   54   61
Changes in Level 3 Commodity Derivatives [Roll Forward]          
Derivative Asset, Current 10   10   11
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Electric Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 58   58   23
Netting, asset [3] (2)   (2)   (2)
Derivative liability, gross 2   2   1
Netting, liability [3] (2)   (2)   (1)
Derivative liability 0   0   0
Changes in Level 3 Commodity Derivatives [Roll Forward]          
Derivative Asset, Current 56   56   21
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Natural Gas Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 3   3   4
Netting, asset [3] 0   0   0
Derivative liability, gross 1   1   1
Netting, liability [3] 0   0   0
Derivative liability 1   1   1
Changes in Level 3 Commodity Derivatives [Roll Forward]          
Derivative Asset, Current 3   3   4
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 1 | Commodity Trading          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 5   5   5
Derivative liability, gross 6   6   6
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 1 | Electric Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 0   0   0
Derivative liability, gross 0   0   0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 1 | Natural Gas Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 0   0   0
Derivative liability, gross 0   0   0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 2 | Commodity Trading          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 18   18   20
Derivative liability, gross 28   28   35
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 2 | Electric Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 0   0   0
Derivative liability, gross 0   0   0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 2 | Natural Gas Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 3   3   4
Derivative liability, gross 1   1   1
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 3 | Commodity Trading          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 7   7   8
Derivative liability, gross 6   6   5
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 3 | Electric Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 58   58   23
Derivative liability, gross 2   2   1
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 3 | Natural Gas Commodity          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 0   0   0
Derivative liability, gross 0   0   0
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 68   68   83
Netting, asset [3] (15)   (15)   (16)
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 1          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 4   4   3
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 2          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 27   27   33
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 3          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 37   37   47
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Other Derivative Instruments | Commodity Trading          
Derivatives, Fair Value [Line Items]          
Derivative asset, gross 68   68   83
Netting, asset [3] (15)   (15)   (16)
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 4   4   3
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 27   27   33
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 37   37   47
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities          
Derivatives, Fair Value [Line Items]          
Derivative liability, gross 72   72   79
Netting, liability [3] (18)   (18)   (18)
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 1          
Derivatives, Fair Value [Line Items]          
Derivative liability, gross 9   9   9
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 2          
Derivatives, Fair Value [Line Items]          
Derivative liability, gross 27   27   30
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 3          
Derivatives, Fair Value [Line Items]          
Derivative liability, gross 36   36   40
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Other Derivative Instruments | Commodity Trading          
Derivatives, Fair Value [Line Items]          
Derivative liability, gross 72   72   79
Netting, liability [3] (18)   (18)   (18)
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 9   9   9
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 27   27   30
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 36   36   40
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Commodity Trading          
Derivatives, Fair Value [Line Items]          
Netting, asset [3] (20)   (20)    
Fair Value, Measurements, Nonrecurring | PPAs          
Derivatives, Fair Value [Line Items]          
Derivative liability [4] 6   6   6
Derivative Liability, Noncurrent [4] $ 13   $ 13   $ 16
[1] Relates primarily to FTR instruments administered by MISO.
[2] Relates to commodity trading and is subject to substantial offsetting losses and gains on derivative instruments categorized as levels 1 and 2 in the consolidated income statement. See above tables for the income statement impact of derivative activity, including commodity trading gains and losses.
[3] NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. At June 30, 2025 and Dec. 31, 2024, derivative assets and liabilities include no obligations to return cash collateral. At June 30, 2025 and Dec. 31, 2024 derivative assets and liabilities include rights to reclaim cash collateral of $3 million and $1 million, respectively. Counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.
[4] NSP-Minnesota currently applies the normal purchase exception to qualifying PPAs. Balance relates to specific contracts that were previously recognized at fair value prior to applying the normal purchase exception, and are being amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.