Financial Instruments - Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Amortized cost
Maturing within one year, Amortized cost	$ 274,352	$ 278,457
Maturing in one to five years, Amortized cost	58,299	91,383
Total available-for-sale securities, Amortized cost	332,651	369,840
Estimated Fair value
Maturing within one year, Estimated fair value	272,851	278,354
Maturing in one to five years, Estimated fair value	57,182	91,118
Total available-for-sale securities, Estimated fair value	$ 330,033	$ 369,472

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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- Definition

Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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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), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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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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