Condensed Financial Statements - Other Investments (Details) - BYD Company Limited common stock [Member] - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Available-for-sale Securities, Equity Securities	$ 1,122	$ 1,435
Parent Company [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Available-for-sale Securities, Equity Securities	$ 1,122	$ 1,435

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.

No definition available.

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