Cash and Available-for-Sale Securities - Summary of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 671,780	$ 2,132,769
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	671,780	2,132,769
Cash and Cash Equivalents	671,780	1,057,769
Investments	0	1,075,000
Cash
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	436,082	517,117
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	436,082	517,117
Cash and Cash Equivalents	436,082	517,117
Investments	0	0
Time deposits
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	130,000	1,360,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	130,000	1,360,000
Cash and Cash Equivalents	130,000	285,000
Investments	0	1,075,000
Money market funds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	105,697	255,652
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	105,697	255,652
Cash and Cash Equivalents	105,697	255,652
Investments	$ 0	$ 0

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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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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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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Sum of the carrying amounts as of the balance sheet date of all investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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