Balance Sheet Components (Schedule of Intangibles, Net) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross	$ 70,144,000	$ 70,144,000
Accumulated Amortization	(69,073,000)	(68,815,000)
Intangibles impairment	(1,071,000)	0	$ 0
Net	0	1,329,000
Technology
Finite-Lived Intangible Assets [Line Items]
Gross	59,799,000	59,799,000
Accumulated Amortization	(58,906,000)	(58,692,000)
Intangibles impairment	(893,000)
Net	0	1,107,000
Other
Finite-Lived Intangible Assets [Line Items]
Gross	10,345,000	10,345,000
Accumulated Amortization	(10,167,000)	(10,123,000)
Intangibles impairment	(178,000)
Net	$ 0	$ 222,000