Fair Value Measurements (Narrative) (Details)	3 Months Ended
	Mar. 31, 2024 USD ($) item	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term investments	$ 22,020,000		$ 24,540,000
Short-term investments	1,585,000		$ 1,046,000
Purchase of short-term investments	300,000,000
Cost method investment, impairment loss	$ 0	$ 0
Proceeds from sale of short-term investments		$ 200,000
Minimum [Member] | Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Average discount rate | item	0.078
Maximum [Member] | Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Average discount rate | item	0.088
Revolving Credit Facility [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Basis spread on variable interest rate	1.125%
Revolving Credit Facility [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Basis spread on variable interest rate	1.50%