Cash and Available-for-Sale Securities - Summary of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,916,942	$ 1,077,344
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	1,916,942	1,077,344
Cash and Cash Equivalents	741,942	637,344
Investments	1,175,000	440,000
Cash
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	406,338	333,172
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	406,338	333,172
Cash and Cash Equivalents	406,338	333,172
Investments	0	0
Time deposits
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,255,000	460,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	1,255,000	460,000
Cash and Cash Equivalents	80,000	20,000
Investments	1,175,000	440,000
Money market funds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	255,604	284,172
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	255,604	284,172
Cash and Cash Equivalents	255,604	284,172
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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