Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Face (par) amount of debt instrument at time of issuance.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of interest capitalized during the period.

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Long-term debt (Details) - USD ($)		12 Months Ended
Long-term debt (Details) - USD ($)	Jun. 11, 2020	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Interest costs capitalized		$ 0	$ 0	$ 0
Notes Due 2030 \| Subordinated Lower Tier II Debt
Debt Instrument [Line Items]
Face amount	$ 100,000,000
Fixed interest rate	5.25%
Basis spread on variable rate	4.43%
Payments of debt issuance costs	$ 2,300,000
Series B Notes Due 2020 \| Subordinated Lower Tier II Debt
Debt Instrument [Line Items]
Repayments of debt	$ 45,000,000