Cash, Cash Equivalents, Restricted Cash and Marketable Securities - Maturities of Marketable Securities Available-for-Sale (Detail) $ in Thousands	Mar. 31, 2021 USD ($)
Amortized Cost
Mature in one year or less	$ 137,849
Mature after one year through two years	15,748
Total amortized cost	153,597
Estimated Fair Value
Mature in one year or less	137,877
Mature after one year through two years	15,742
Total estimated fair value	$ 153,619

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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