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Equity (Narrative) (Details) - USD ($) |  |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 01, 2024 | Sep. 30, 2024 | Sep. 27, 2024 | Sep. 17, 2024 | Sep. 11, 2024 | May 22, 2024 | Feb. 22, 2024 | Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | Feb. 23, 2024 | Mar. 15, 2024 | Dec. 31, 2023 | Dec. 01, 2023 | Jun. 15, 2023
Preferred Stock, Shares Authorized |  | 20,000,000 |  |  |  |  |  | 20,000,000 |  | 20,000,000 |  |  |  | 20,000,000 |  |
Preferred Stock, Shares Outstanding |  | 0 |  |  |  |  |  | 0 |  | 0 |  |  |  | 40,000 |  |
Preferred Stock, Par or Stated Value Per Share |  | $ 0.01 |  |  |  |  |  | $ 0.01 |  | $ 0.01 |  |  | $ 25,000 | $ 0.01 | $ 0.01 |
Preferred Stock Shares Redeemed |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |
Common Stock, Shares, Issued |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 33,898,837 |
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share | $ 34.06 | $ 34.32 | $ 34.01 | $ 25.77 | $ 28.79 | $ 28.87 |  | $ 33.72 |  |  |  | $ 25.78 |  |  |  |
Preferred Stock, Liquidation Preference Per Share |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000
Preferred Stock Redemption Premium |  |  |  |  |  |  |  | $ 0 | $ 0 | $ 14,000,000.0 | $ 6,200,000 |  |  |  |  |
Pension Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan, Plan Assets, Contributions by Employer |  |  |  |  |  |  |  |  |  | 1,900,000 | 2,600,000 |  |  |  |  |
Other Postretirement Benefit Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan, Plan Assets, Contributions by Employer |  |  |  |  |  |  |  |  |  | 18,300,000 | $ 16,700,000 |  |  |  |  |
At The Market Program |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock Aggregate Sale Price |  |  |  |  |  |  | $ 900,000,000.0 |  |  |  |  |  |  |  |  |
ATM Program Equity Remaining Available for Issuance |  |  |  |  |  |  |  |  |  | $ 297.7 |  |  |  |  |  |
Forward February 23 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock Aggregate Sale Price |  |  |  |  |  |  |  | 199,900,000 |  |  |  |  |  |  |  |
Forward Contract Indexed to Issuer's Equity, Shares |  |  |  |  |  |  |  |  |  |  |  | 7,757,951 |  |  |  |
Forward September 24 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock Aggregate Sale Price |  |  |  |  |  |  |  | $ 50,400,000 |  |  |  |  |  |  |  |
Forward Contract Indexed to Issuer's Equity, Shares |  |  | 1,495,949 |  |  |  |  |  |  |  |  |  |  |  |  |
Series A Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Shares Outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 400,000
Preferred Stock, Redemption Amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 400,000,000
Preferred Stock, Dividends Per Share, Declared |  |  |  |  |  |  |  |  | $ 28.25 | $ 0 |  |  |  |  |  |
Series B Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Dividends Per Share, Declared |  |  |  |  |  |  |  | $ 0 | $ 406.25 | $ 406.25 | $ 1,625 |  |  |  |  |
Preferred Stock Redemption Premium |  |  |  |  |  |  |  |  |  | $ 14,000,000 |  |  |  |  |  |
Series B-1 Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Par or Stated Value Per Share |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.01 |  |  |
Preferred Stock, Redemption Amount |  |  |  |  |  |  |  |  |  |  |  |  | $ 500,000,000 |  |  |
Preferred Stock, Shares Issued |  | 20,000 |  |  |  |  |  | 20,000 |  | 20,000 |  |  | 20,000 |  |  |
Series C Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Shares Outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 862,500 |

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