Short-term Investment Securities (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Short-term investment securities	$ 109,494,000		$ 109,494,000		$ 107,115,000
Realized gain (loss) on available-for-sale securities	0	$ 0	0	$ 0
Accumulated other comprehensive loss	294,000		294,000		596,000
Debt Securities, Available For Sale
Debt Securities, Available-for-sale [Line Items]
Short-term investment securities	109,500,000		$ 109,500,000		107,100,000
Weighted-average fixed rate			4.10%	0.30%
Unrealized gain (loss) on investment securities, net of deferred taxes	36,000	$ (173,000)	$ 221,000	$ (435,000)
Accumulated other comprehensive loss	$ (46,000)		$ (46,000)		$ (267,000)