Fair Value Measurements (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($) item	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term investments	$ 31,569		$ 40,696
Short-term investments	1,141		$ 1,331
Purchase of short-term investments	1,000,000	$ 501,600
Proceeds from sale of short-term investments	$ 1,000,000	$ 481,600
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	0.065
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%