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v3.25.0.1

Short-Term and Long-Term Borrowings - Narrative (Details) - USD ($) |  | 12 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 28, 2024 | Dec. 31, 2024 | Dec. 11, 2024 | Dec. 31, 2023
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  | $ 390,000,000 |  |
Debt, weighted average interest rate (as a percent) |  | 5.61% |  | 6.70%
Long-term debt |  | $ 943,734,000 |  | $ 824,059,000
Long-term debt |  | $ 947,000,000 |  | 827,000,000
Debt instrument, redemption price, percentage of principal amount redeemed (as a percent) | 10.00% |  |  |
Debt instrument, redemption price (as a percent) | 100.00% | 100.00% |  |
Senior Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Long-term debt | $ 120,000,000.0 |  |  |
Minimum |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt instrument, basis spread on variable rate (as a percent) |  | 0.00% |  |
Debt to total capitalization ratio |  | 0.60 |  |
Interest and dividend coverage ratio |  | 1.50 |  |
Maximum |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt instrument, basis spread on variable rate (as a percent) |  | 2.00% |  |
Debt to total capitalization ratio |  | 0.65 |  |
OTC Credit Agreement |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  | $ 170,000,000 |  |
Line of credit facility, increased current borrowing capacity, accordion provision |  |  | $ 290,000,000 |
OTP Credit Agreement |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  | 220,000,000 |  |
Line of credit facility, increased current borrowing capacity, accordion provision |  |  | 300,000,000 |
Series 2024A Senior Unsecured Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Long-term debt |  | $ 60,000,000 |  | 0
Interest rate (as a percent) |  | 5.48% |  |
Series 2024A Senior Unsecured Notes | Senior Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Long-term debt | $ 60,000,000.0 |  |  |
Interest rate (as a percent) | 5.48% |  |  |
Series 2024B Senior Unsecured Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Long-term debt |  | $ 60,000,000 |  | $ 0
Interest rate (as a percent) |  | 5.77% |  |
Series 2024B Senior Unsecured Notes | Senior Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Long-term debt | $ 60,000,000.0 |  |  |
Interest rate (as a percent) | 5.77% |  |  |
Revolving Credit Facility | OTC Credit Agreement |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  | 170,000,000 |
Revolving Credit Facility | OTP Credit Agreement |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  | 220,000,000 |
Letter of Credit | OTC Credit Agreement |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  | 40,000,000 |
Letter of Credit | OTP Credit Agreement |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  | $ 50,000,000 |

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