Common Stock and Stock-Based Compensation- Summary of Activity Under Equity Plans and Related Information (Details) - $ / shares	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options, Beginning balance	75,000,000
Number of Options, Granted	0	0	0
Number of Options, Exercised	(29,000,000)
Number of Options, Forfeited or cancelled	(1,000,000)
Number of Options, Ending balance	45,000,000	75,000,000
Weighted-Average Exercise Price, Beginning balance	$ 0.234
Weighted-Average Exercise Price, Exercised	0.209
Weighted-Average Exercise Price, Forfeited or cancelled	0.032
Weighted-Average Exercise Price, Ending balance	$ 0.254	$ 0.234
Weighted-Average Remaining Contractual Term	2 years 6 months	3 years 2 months 12 days
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Stock Units, Beginning balance	30,000,000
Number of Restricted Stock Units, Granted	37,000,000
Number of Restricted Stock Units, Vested	(11,000,000)		0
Number of Restricted Stock Units, Forfeited or cancelled	(8,000,000)
Number of Restricted Stock Units, Ending balance	48,000,000	30,000,000

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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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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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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