Long-Term Debt (Components of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt	$ 29,471	$ 28,042
Less current portion of long-term debt	1,500	1,000
Long-term debt excluding current portion	27,971	27,042
Notes 2.350% To 10.20%, interest payable semi-annually, due through 2059 [Member] \| Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 24,258	$ 23,259
Notes 2.350% To 10.20%, interest payable semi-annually, due through 2059 [Member] \| Notes [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated interest rate	2.35%
Notes 2.350% To 10.20%, interest payable semi-annually, due through 2059 [Member] \| Notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated interest rate	10.20%
Notes 2.350% To 10.20%, interest payable semi-annually, due through 2059 [Member] \| Notes [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted average interest rate	4.60%	4.60%
Debenture, 7.75% interest payable semi-annually, due 2027 [Member] \| Debenture [Member]
Debt Instrument [Line Items]
Long-term debt	$ 42	$ 42
Stated interest rate	7.75%
Euro notes, 1.000% to 3.125%, interest payable annually, due through 2031 [Member] \| Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Long-term debt	$ 5,171	$ 4,741
Euro notes, 1.000% to 3.125%, interest payable annually, due through 2031 [Member] \| Notes Payable, Other Payables [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated interest rate	1.00%
Euro notes, 1.000% to 3.125%, interest payable annually, due through 2031 [Member] \| Notes Payable, Other Payables [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated interest rate	3.125%
Euro notes, 1.000% to 3.125%, interest payable annually, due through 2031 [Member] \| Notes Payable, Other Payables [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted average interest rate	2.00%	2.00%

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

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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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