Debt (Narrative) (Details)						12 Months Ended
	Feb. 13, 2023	Oct. 15, 2022	Apr. 18, 2022 USD ($)	May 15, 2021 USD ($)	Oct. 02, 2012 $ / shares	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Feb. 08, 2023 USD ($)	Dec. 01, 2022 USD ($)	Nov. 04, 2022 USD ($)	May 16, 2022 USD ($)	Apr. 29, 2022 USD ($)	Mar. 17, 2021 USD ($)	Nov. 23, 2020 USD ($)	Aug. 17, 2020 USD ($)	May 05, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 09, 2019 USD ($)	Oct. 09, 2012 USD ($)
Debt Instrument [Line Items]
Long-term debt face amount						$ 63,000,000
Gain (loss) on extinguishment of debt						$ 0	$ (21,000,000)	$ (36,000,000)
Debt Instrument, Convertible, Conversion Ratio, Shares						14.3238
Debt Instrument, Convertible, Conversion Price | $ / shares						$ 69.8139
Repayments of Long-term Debt						$ 1,899,000,000	1,068,000,000	1,932,000,000
Interest paid						878,000,000	822,000,000	794,000,000
Future maturities of debt in 2023						1,500,000,000
Future maturities of debt in 2024						1,647,000,000
Future maturities of debt in 2025						1,650,000,000
Future maturities of debt in 2026						746,000,000
Future maturities of debt in 2027						1,592,000,000
Future maturities of debt Thereafter						16,714,000,000
Long-term debt						23,849,000,000	22,756,000,000
Total shareholders' equity						36,307,000,000	36,060,000,000
Retained Earnings [Member]
Debt Instrument [Line Items]
Total shareholders' equity						29,724,000,000	27,088,000,000	23,802,000,000										$ 22,538,000,000
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2020-06 | Retained Earnings [Member]
Debt Instrument [Line Items]
Long-term debt							31,000,000
Deferred Tax and Other Liabilities, Noncurrent							(8,000,000)
Total shareholders' equity							(23,000,000)
5-Year Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity			$ 4,000,000,000				2,500,000,000
2021 364-Day Facility
Debt Instrument [Line Items]
Line of Credit Facility, Description			Also on April 18, 2022, concurrently with the amendment and restatement of the 5-Year Facility, we terminated our 364-day senior revolving credit facility that provided for credit in the amount of $1,000, which was scheduled to mature in June 2022
2021 364-Day Facility | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity						$ 1,000,000,000
Senior Unsecured Notes [Member] | 3.700%, due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate				3.70%
Debt, Redemption amount				$ 700,000,000
Debt Instrument, Redemption, Description				at a redemption price equal to 100% of the aggregate principal amount of the notes being redeemed, plus accrued and unpaid interest.
Senior Unsecured Notes [Member] | 2.950% due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						2.95%				2.95%
Repurchased face amount										$ 750,000,000
Long-term debt						$ 0	749,000,000
Senior Unsecured Notes [Member] | .0450% due 2023 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						0.45%								0.45%
Long-term debt face amount														$ 500,000,000
Long-term debt						$ 500,000,000	499,000,000
Senior Unsecured Notes [Member] | 1.500% due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						1.50%								1.50%
Long-term debt face amount														$ 750,000,000
Long-term debt						$ 746,000,000	745,000,000
Senior Unsecured Notes [Member] | 2.550% due 2031 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						2.55%								2.55%
Long-term debt face amount														$ 1,000,000,000
Long-term debt						$ 968,000,000	992,000,000
Senior Unsecured Notes [Member] | 3.600% due 2051 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						3.60%								3.60%
Long-term debt face amount														$ 1,250,000,000
Long-term debt						$ 1,233,000,000	1,232,000,000
Senior Unsecured Notes [Member] | 2.500% due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate															2.50%
Repurchased face amount															$ 900,000,000
Senior Unsecured Notes [Member] | 4.350%, due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate																4.35%
Repurchased face amount																$ 700,000,000
Senior Unsecured Notes [Member] | 2.375%, due 2025 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate																	2.375%		2.375%
Long-term debt face amount																	$ 400,000,000		$ 850,000,000
Senior Unsecured Notes [Member] | 2.250%, due 2030 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						2.25%											2.25%
Long-term debt face amount																	$ 1,100,000,000
Long-term debt						$ 1,071,000,000	1,089,000,000
Senior Unsecured Notes [Member] | 3.125% due 2050 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						3.125%											3.125%
Long-term debt face amount																	$ 1,000,000,000
Long-term debt						$ 988,000,000	987,000,000
Senior Unsecured Notes [Member] | 3.125%, due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						3.125%						3.125%
Repurchased face amount												$ 850,000,000
Long-term debt						$ 0	850,000,000
Senior Unsecured Notes [Member] | 4.100% due 2032 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						4.10%							4.10%
Long-term debt face amount													$ 600,000,000
Long-term debt						$ 595,000,000	0
Senior Unsecured Notes [Member] | 5.350% due 2025 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						5.35%					5.35%
Long-term debt face amount											$ 400,000,000
Long-term debt						$ 398,000,000	0
Senior Unsecured Notes [Member] | 5.500% due 2032 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						5.50%					5.50%
Long-term debt face amount											$ 650,000,000
Long-term debt						$ 644,000,000	0
Senior Unsecured Notes [Member] | 4.550% due 2052 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						4.55%							4.55%
Long-term debt face amount													$ 700,000,000
Long-term debt						$ 689,000,000	0
Senior Unsecured Notes [Member] | 6.100% due 2052 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						6.10%					6.10%
Long-term debt face amount											$ 750,000,000
Long-term debt						$ 741,000,000	0
Senior Unsecured Notes [Member] | 4.900 % due 2026 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument interest rate									4.90%
Long-term debt face amount									$ 500,000,000
Senior Unsecured Notes [Member] | 4.750% due 2033 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument interest rate									4.75%
Long-term debt face amount									$ 1,000,000,000
Senior Unsecured Notes [Member] | 5.125% due 2053 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument interest rate									5.125%
Long-term debt face amount									$ 1,100,000,000
Other senior unsecured notes [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount						52,000,000	79,000,000
Early repayment of senior debt						67,000,000	109,000,000
Gain (loss) on extinguishment of debt						15,000,000	(30,000,000)
Commercial Paper [Member]
Debt Instrument [Line Items]
Commercial paper authorized						4,000,000,000	3,500,000,000
Commercial paper						$ 0	$ 300,000,000
Weighted average interest rate on commercial paper borrowings							0.15%
Senior Convertible Debentures [Member] | 2.750%, due 2042 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate						2.75%														2.75%
Long-term debt face amount						$ 1,000														$ 1,500,000,000
Gain (loss) on extinguishment of debt							$ (6,000,000)	(6,000,000)
Number of trading days in 30 day period greater than 130%						20
Number of trading days exceeding 130%						30 days
Product of Conversion to Stock Price						130.00%
Measurement Period for testing						10 days
Percent of Conversion Price to Closing Price						98.00%
Earliest Date for Conversion						Apr. 15, 2042
Maturity date on long-term debt						Oct. 15, 2042
Date debentures redeemable at our option						Oct. 20, 2022
Debt Instrument, Convertible, Conversion Ratio, Shares					13.2319
Conversion premium (%)					25.00%
Closing Price Company Stock | $ / shares					$ 60.46	$ 512.97
Debt Instrument, Convertible, Conversion Price | $ / shares					$ 75.575
Aggregate principal amount of convertible debentures surrendered for conversion						$ 41,000,000	54,000,000	56,000,000
Repayments of Long-term Debt						299,000,000	302,000,000	222,000,000
If-converted value per dollar above the conversion price						402,000,000
Interest expense						2,000,000	4,000,000	6,000,000
Interest expense resulting from the stated interest rate						2,000,000	3,000,000	5,000,000
Interest expense resulting from amortization of the debt discount						0	1,000,000	$ 1,000,000
Long-Term Debt, Contingent Payment of Principal or Interest		The Debentures also have a contingent interest feature that requires us to pay additional interest based on certain thresholds and for certain events, as defined in the Indenture, beginning on October 15, 2022. As of October 15, 2022, one of these events had occurred and contingent interest began accruing on the Debentures at a rate of 0.50% of the average trading price of a Debenture for the ten consecutive trading days ended October 14, 2022. Contingent interest will be payable on April 15, 2023, to holders of the Debentures as of the April 1, 2023 record date.
Long-term debt						63,000,000	72,000,000
Senior Convertible Debentures [Member] | 2.750%, due 2042 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Debt Instrument, Redemption Period, End Date	Mar. 15, 2023
Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Short-term FHLB borrowings outstanding						$ 265,000,000	275,000,000
Debt instrument interest rate						4.24%
Subsidiary Credit Facilities
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity						$ 200,000,000
Short-term borrowings							$ 0
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Covenant Description						Our ability to borrow under the 5-Year Facility is subject to compliance with certain covenants, including covenants requiring us to maintain a defined debt-to-capital ratio of not more than 60%, subject to increase in certain circumstances set forth in the credit agreement for the 5-Year Facility.
Debt Instrument, Covenant Compliance						As of December 31, 2022, our debt-to-capital ratio, as defined and calculated under the 5-Year Facility, was 39.9%. We do not believe the restrictions contained in our 5-Year Facility covenants materially affect our financial or operating flexibility. As of December 31, 2022, we were in compliance with all of our debt covenants under the 5-Year Facility.