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v3.25.0.1

Debt - Narrative (Details) |  |  | 1 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 10, 2022 USD ($) deferral_period | Jun. 04, 2019 USD ($) | Jun. 30, 2017 USD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Feb. 15, 2022 USD ($) | Sep. 22, 2020 | Jun. 08, 2018 USD ($) | Feb. 28, 2015 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Long-term Debt |  |  |  | $ 1,391,600,000 | $ 1,389,200,000 |  |  |  |  |
Interest expense |  |  |  | 56,900,000 | 56,100,000 | $ 54,700,000 |  |  |  |
Interest paid including facility fees |  |  |  | $ 54,500,000 | 54,500,000 | $ 51,500,000 |  |  |  |
Senior Notes, 4.35 Percent Due February 15, 2025 | Senior Notes |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Stated interest rate, percentage |  |  |  | 4.35% |  |  |  |  |  |
Long-term debt, gross |  |  |  | $ 450,000,000.0 |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  | $ 250,000,000.0
Increase in debt instrument |  |  | $ 200,000,000.0 |  |  |  |  |  |  |
Long-term Debt |  |  |  | 0 | 449,600,000 |  |  |  |  |
Senior Notes, 2.400 Percent Due September 30, 2030 | Senior Notes |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Stated interest rate, percentage |  |  |  |  |  |  |  | 2.40% |  |
Long-term debt, gross |  |  |  | 400,000,000.0 |  |  |  |  |  |
Proceeds from debt, net of issuance costs |  |  |  | 395,800,000 |  |  |  |  |  |
Debt instrument, effective interest rate |  |  |  |  |  |  |  | 2.52% |  |
Long-term Debt |  |  |  | 397,500,000 | 397,000,000.0 |  |  |  |  |
Senior Notes, 3.800 Percent Due February 23, 2032 |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Long-term Debt |  |  |  |  |  |  | $ 395,100,000 |  |  |
Senior Notes, 3.800 Percent Due February 23, 2032 | Senior Notes |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Stated interest rate, percentage |  |  |  |  |  |  | 3.80% |  |  |
Long-term debt, gross |  |  |  | 400,000,000 |  |  |  |  |  |
Debt instrument, effective interest rate |  |  |  |  |  |  |  | 3.95% |  |
Long-term Debt |  |  |  | 396,500,000 | 396,000,000.0 |  |  |  |  |
5.875% Fixed-Rate Reset Junior Subordinated Debentures due 2062 |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Long-term Debt | $ 144,700,000 |  |  |  |  |  |  |  |  |
5.875% Fixed-Rate Reset Junior Subordinated Debentures due 2062 | Senior Notes |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Long-term debt, gross |  |  |  | 150,000,000 |  |  |  |  |  |
5.875% Fixed-Rate Reset Junior Subordinated Debentures due 2062 | Junior Debt |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Stated interest rate, percentage | 5.875% |  |  |  |  |  |  |  |  |
Long-term Debt |  |  |  | 147,700,000 | 146,600,000 |  |  |  |  |
Debt instrument, basis spread on variable rate | 4.14% |  |  |  |  |  |  |  |  |
Interest deferrals, number of deferral periods | deferral_period | 1 |  |  |  |  |  |  |  |  |
Interest deferrals, period (up to) | 5 years |  |  |  |  |  |  |  |  |
5.875% Fixed-Rate Reset Junior Subordinated Debentures due 2062 | Junior Debt | Five-Year Treasury Rate |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Debt instrument, basis spread on variable rate | 4.14% |  |  |  |  |  |  |  |  |
Second Amended and Restated Credit Agreement | Notes Payable under Revolving Credit Agreement | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Maximum Capacity Amount |  | $ 800,000,000.0 |  | $ 512,000,000.0 |  |  |  |  | $ 600,000,000.0 |
Increase in line of credit facility |  | 200,000,000.0 |  |  |  |  |  |  |  |
Line of credit, outstanding |  |  |  |  | $ 0 |  |  |  |  |
Debt issuance costs |  | 2,200,000 |  |  |  |  |  |  |  |
Unamortized debt issuance expense |  | $ 1,100,000 |  |  |  |  |  |  |  |

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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
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- Definition Amount of increase (decrease) of the credit facility. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(f)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 + Details
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
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- Definition Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-4 + Details
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- Definition The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 14 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-14 + Details
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- Definition The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset. + References No definition available. + Details
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