Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

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The price per share of the conversion feature embedded in the debt instrument.

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Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

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The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

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Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Face (par) amount of debt instrument at time of issuance.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount of unamortized debt discount (premium) and 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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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Fair Value Instruments - Convertible Debt (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) $ / shares	Dec. 31, 2020 USD ($)	May 01, 2020 USD ($)
Debt Instrument, Convertible, Conversion Price \| $ / shares	$ 38.48
Debt Instrument, Convertible, Remaining Discount Amortization Period	5 years
1.250 Convertible Senior Notes due 2025
Debt Instrument, Convertible, Conversion Ratio	25.9909
Debt Instrument, Convertible, Conversion Price \| $ / shares	$ 38.48
1.250 Convertible Senior Notes due 2025 \| Convertible Debt [Member]
Unamortized debt discount	$ (337)	$ (355)
Net carrying amount	1,963	1,945
Debt Instrument, Convertible, Carrying Amount of Equity Component	$ 403	403
Debt Instrument, Interest Rate, Effective Percentage	5.20%
Interest Expense, Debt	$ 28
Debt Instrument, Convertible, If-converted Value in Excess of Principal	881
1.250 Convertible Senior Notes due 2025 \| Convertible Debt [Member] \| Principal Amount
Principal amount	2,300	$ 2,300
1.250 Convertible Senior Notes due 2025 \| Convertible Debt [Member] \| Date of Issuance
Debt Instrument, Face Amount			$ 2,300
1.250 Convertible Senior Notes due 2025 \| Convertible Debt [Member] \| Contractual Coupon Interest Expense
Interest Expense, Debt	7
1.250 Convertible Senior Notes due 2025 \| Convertible Debt [Member] \| Non-Cash Amortization of Debt Discount
Interest Expense, Debt	19
1.250 Convertible Senior Notes due 2025 \| Convertible Debt [Member] \| Non-Cash Amortization of Debt Issuance Costs
Interest Expense, Debt	$ 2
1.250 Convertible Senior Notes due 2025 \| Unsecured Debt
Stated interest rate	1.25%