Investments - Available-for-sale securities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 736,983	$ 1,242,933
Gross Unrealized Gains		20
Gross Unrealized Losses	(21,077)	(2,688)
Fair Value	715,906	1,240,265
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	233,386	228,614
Gross Unrealized Losses	(7,665)	(2,232)
Fair Value	225,721	226,382
U.S. Treasuries
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	503,597	1,014,319
Gross Unrealized Gains		20
Gross Unrealized Losses	(13,412)	(456)
Fair Value	$ 490,185	$ 1,013,883

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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Amortized cost of 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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