3. Cash and Marketable Securities (Details) - Marketable Securities - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 145,310		$ 375,797
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1		91
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,327		402
Marketable Securities, Allowance for Credit Losses	40	$ 87	97
Marketable securities	143,944		375,389
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Losses, Beginning Balance	97	121
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease)	64	201
Debt Securities, Available-for-sale, Allowance for Credit Loss, Securities Sold	(121)	(235)
Debt Securities, Available-for-sale, Allowance for Credit Losses, Ending Balance	40	$ 87
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year	135,242
Debt securities, Available-for-sale, Debt Maturities, Rolling Year One Through Two	0
Debt securities, Available-for-sale, Debt Maturities, Rolling Year Two Through Three	0
Debt Securities, Available-for-sale, Maturities, Rolling Year Three Through Four	4,548
Debt Securities, Available-for-sale, Maturities, Rolling Year Four Through Five	0
Debt Securities, Available-for-sale, Maturities, Rolling Year More Than Five	4,154
Foreign debt [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	52,208		103,263
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1		81
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	31		18
Marketable Securities, Allowance for Credit Losses	17		9
Marketable securities	52,161		103,317
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Losses, Beginning Balance	9
Debt Securities, Available-for-sale, Allowance for Credit Losses, Ending Balance	17
U.S. debt [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	10,000		19,003
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0		10
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,296		384
Marketable Securities, Allowance for Credit Losses	2		2
Marketable securities	8,702		18,627
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Losses, Beginning Balance	2
Debt Securities, Available-for-sale, Allowance for Credit Losses, Ending Balance	2
Time deposits [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	83,102		253,531
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0		0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0		0
Marketable Securities, Allowance for Credit Losses	21		86
Marketable securities	83,081		$ 253,445
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Losses, Beginning Balance	86
Debt Securities, Available-for-sale, Allowance for Credit Losses, Ending Balance	$ 21

Debt Securities, Available-for-sale, Maturities, Rolling Year Four Through Five

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Debt Securities, Available-for-sale, Maturities, Rolling Year More Than Five

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Debt Securities, Available-for-sale, Maturities, Rolling Year One Through Two

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Debt Securities, Available-for-sale, Maturities, Rolling Year Three Through Four

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Debt Securities, Available-for-sale, Maturities, Rolling Year Two Through Three

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of decrease in allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from sale.

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