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FAIR VALUE MEASUREMENTS - Fixed Income Securities Held in Nuclear Trusts (Details) - Spent Nuclear Fuel and Decommissioning Trusts $ in Millions | Mar. 31, 2025 USD ($)
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Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
Within 1 year | $ 344.0
After 1 year through 5 years | 601.9
After 5 years through 10 years | 268.9
After 10 years | 353.3
Total | 1,568.1
I&M |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
Within 1 year | 344.0
After 1 year through 5 years | 601.9
After 5 years through 10 years | 268.9
After 10 years | 353.3
Total | $ 1,568.1

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