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Balance Sheet Components - Summary of Contractual Maturities of Available-for-Sale Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Available For Sale Securities Debt Maturities [Abstract]
Within one year - Bond and mutual funds	$ 8,144
Equity investments	244
Total investments	$ 8,388	$ 468,609

X

- Definition

Available for sale securities bond and mutual funds maturing within one year.

+ References

No definition available.

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X

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

No definition available.

+ Details

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- References

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Balance Type:	na
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X

- Definition

Amount of equity securities categorized neither as held-to-maturity nor as trading.

+ References

No definition available.

+ Details

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