Fair Value Measurements (Summary of Valuation of Company's Financial Instruments by Various Levels) (Parenthetical) (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 106,931,000	$ 80,925,000
Other non-current assets	17,326,000	97,793,000
Convertible debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 173,000	173,000
Other non-current assets		$ 173,000