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
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Investment Securities, Equity Securities with Readily Determinable Fair Values and Other Investments
Equity Securities	$ 5,537,000		$ 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	(36,000)	$ 67,000
Unrealized (losses) gains recognized during the reporting period on equity securities still held at the reporting date	$ (36,000)	$ 67,000