Fair value measurements - Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Mortgage revenue bonds - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 14,076	$ 14,630	$ 14,358	$ 14,902
Principal payments received	(141)	(136)	(423)	(408)
Purchases	0	0	0	0
Unrealized gain (loss) included in other comprehensive income	0	0	0	0
Ending balance	$ 13,935	$ 14,494	$ 13,935	$ 14,494

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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-Topic 820
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- Definition

Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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