Financing Activities - Interest Expense (Details) - Convertible Debt - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Debt Instrument [Line Items]
Non-cash amortization of the debt discount	$ 0	$ 19
Non-cash amortization of debt issuance costs	3	2
Contractual coupon interest	6	7
Total interest expense	$ 9	$ 28

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of amortization expense attributable to debt issuance costs.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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