Investment Securities (Narrative) (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) investment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
Long-term investments	$ 46,760,000	$ 44,959,000
Proceeds from sale or liquidation of long-term investments	5,530,000	9,266,000	$ 11,509,000
In-transit redemptions	88,000
Proceeds from long-term equity method investment	55,000
Investment	$ 5,000,000
Number of investments not qualify for the NAV practical expedient | investment	2,000
Equity securities and other long-term investments at cost	$ 7,555,000	2,755,000
Impairment or other adjustments related to observable price changes	$ 0	0	0
Dividends received		51,000
Proceeds from long-term equity method investment, gross			50,000
Mutual fund and hedge funds | Minimum
Debt Securities, Available-for-sale [Line Items]
Equity method ownership percentage	7.54%
Mutual fund and hedge funds | Maximum
Debt Securities, Available-for-sale [Line Items]
Equity method ownership percentage	38.67%
Quoted Prices in Active Markets for Identical Assets (Level 1) | Unfunded commitments
Debt Securities, Available-for-sale [Line Items]
Long-term investments	$ 303,000
NAV
Debt Securities, Available-for-sale [Line Items]
Proceeds from sale or liquidation of long-term investments	$ 5,330,000	$ 4,971,000	11,509,000
Proceeds from long-term equity method investment			$ 11,642,000