Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	$ 515,460	$ 717,043
Gross Unrealized Gains	58	411
Gross Unrealized Losses	(70)	(120)
Debt Securities, Available-for-sale	515,448	717,334
Cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	132,753	137,783
Debt Securities, Available-for-sale	132,753	137,783
Cash equivalents [Member] \| Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	91,433	40,027
Debt Securities, Available-for-sale	91,433	40,027
Cash equivalents [Member] \| Time deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	41,320	36,756
Debt Securities, Available-for-sale	41,320	36,756
Cash equivalents [Member] \| Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost		61,000
Debt Securities, Available-for-sale		61,000
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	322,605	442,277
Gross Unrealized Gains	58	259
Gross Unrealized Losses	(29)	(63)
Debt Securities, Available-for-sale	322,634	442,473
Short-term investments [Member] \| Time deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	32,439	28,302
Debt Securities, Available-for-sale	32,439	28,302
Short-term investments [Member] \| Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	118,300	264,000
Gross Unrealized Gains	10	12
Gross Unrealized Losses	(2)	(19)
Debt Securities, Available-for-sale	118,308	263,993
Short-term investments [Member] \| Government and corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	171,866	149,975
Gross Unrealized Gains	48	247
Gross Unrealized Losses	(27)	(44)
Debt Securities, Available-for-sale	171,887	150,178
Long-term investments [Member] \| Government and corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	60,102	136,983
Gross Unrealized Gains		152
Gross Unrealized Losses	(41)	(57)
Debt Securities, Available-for-sale	$ 60,061	$ 137,078

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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