Investments - Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Amortized Cost
Within one year	$ 670,584
After one through five years	572,349
Amortized Cost	1,242,933
Fair Value
Within one year	670,306
After one through five years	569,959
Fair Value	1,240,265
Accrued interest income	$ 3,700	$ 0

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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Amount 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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