Balance Sheet Components (Schedule of Amortized Cost and Estimated Fair Market Value of Investments Classified as Available-for-Sale Excluding Cash Equivalents) (Parentheticals) (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Short-term investments	$ 106,931,000	$ 80,925,000
Other non-current assets	17,326,000	97,793,000
Convertible debt securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments	$ 173,000	173,000
Other non-current assets		$ 173,000