Maturities of Marketable Securities Available-for-Sale (Detail) $ in Thousands	Mar. 31, 2019 USD ($)
Amortized Cost
Mature in one year or less	$ 71,083
Mature after one year through two years	0
Total amortized cost	71,083
Estimated Fair Value
Mature in one year or less	71,083
Mature after one year through two years	0
Total estimated fair value	$ 71,083

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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