Investment Securities, Equity Securities with Readily Determinable Fair Values and Other Investments - Unrealized and realized gains and losses recognized in net income on equity securities (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Investment Securities, Equity Securities with Readily Determinable Fair Values and Other Investments
Equity Securities	$ 5,545,000		$ 5,545,000		$ 5,573,000
Summary of unrealized and realized gains and losses recognized in net income on equity securities
Net gains (losses) recognized during the period on equity securities	8,000	$ 22,000	(28,000)	$ 89,000
Unrealized (losses) gains recognized during the reporting period on equity securities still held at the reporting date	$ 8,000	$ 22,000	$ (28,000)	$ 89,000

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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+ Details