Debt (Carrying Value Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 01, 2022	Nov. 04, 2022	May 16, 2022	Apr. 29, 2022	Dec. 31, 2021	Mar. 17, 2021	May 05, 2020	Oct. 09, 2012
Debt Instrument [Line Items]
Long-term debt	$ 23,849					$ 22,756
Current portion of long-term debt	(1,500)					(1,599)
Long-term debt, less current portion	22,349					21,157
Senior Unsecured Notes [Member] | 2.950% due 2022 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 0					749
Interest rate on long-term debt	2.95%	2.95%
Senior Unsecured Notes [Member] | 3.125%, due 2022 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 0					850
Interest rate on long-term debt	3.125%			3.125%
Senior Unsecured Notes [Member] | 3.300%, due 2023 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,000					1,014
Interest rate on long-term debt	3.30%
Senior Unsecured Notes [Member] | .0450% due 2023 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 500					499
Interest rate on long-term debt	0.45%						0.45%
Senior Unsecured Notes [Member] | 3.350% due 2024 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 849					848
Interest rate on long-term debt	3.35%
Senior Unsecured Notes [Member] | 3.500%, due 2024 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 798					797
Interest rate on long-term debt	3.50%
Senior Unsecured Notes [Member] | 2.375%, due 2025 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,252					1,253
Interest rate on long-term debt	2.375%
Senior Unsecured Notes [Member] | 5.350% due 2025 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 398					0
Interest rate on long-term debt	5.35%		5.35%
Senior Unsecured Notes [Member] | 1.500% due 2026 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 746					745
Interest rate on long-term debt	1.50%						1.50%
Senior Unsecured Notes [Member] | 3.650% due 2027 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,592					1,592
Interest rate on long-term debt	3.65%
Senior Unsecured Notes [Member] | 4.101%, due 2028 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,234					1,251
Interest rate on long-term debt	4.101%
Senior Unsecured Notes [Member] | 2.875%, due 2029 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 820					820
Interest rate on long-term debt	2.875%
Senior Unsecured Notes [Member] | 2.250%, due 2030 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,071					1,089
Interest rate on long-term debt	2.25%							2.25%
Senior Unsecured Notes [Member] | 2.550% due 2031 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 968					992
Interest rate on long-term debt	2.55%						2.55%
Senior Unsecured Notes [Member] | 4.100% due 2032 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 595					0
Interest rate on long-term debt	4.10%				4.10%
Senior Unsecured Notes [Member] | 5.500% due 2032 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 644					0
Interest rate on long-term debt	5.50%		5.50%
Senior Unsecured Notes [Member] | 5.950%, due 2034 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 334					334
Interest rate on long-term debt	5.95%
Senior Unsecured Notes [Member] | 5.850%, due 2036 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 396					396
Interest rate on long-term debt	5.85%
Senior Unsecured Notes [Member] | 6.375%, due 2037 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 364					364
Interest rate on long-term debt	6.375%
Senior Unsecured Notes [Member] | 5.800%, due 2040 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 114					114
Interest rate on long-term debt	5.80%
Senior Unsecured Notes [Member] | 4.625%, due 2042 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 859					859
Interest rate on long-term debt	4.625%
Senior Unsecured Notes [Member] | 4.650%, due 2043 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 974					974
Interest rate on long-term debt	4.65%
Senior Unsecured Notes [Member] | 4.650%, due 2044 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 767					767
Interest rate on long-term debt	4.65%
Senior Unsecured Notes [Member] | 5.100%, due 2044 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 548					548
Interest rate on long-term debt	5.10%
Senior Unsecured Notes [Member] | 4.375% due 2047 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,388					1,387
Interest rate on long-term debt	4.375%
Senior Unsecured Notes [Member] | 4.550%, due 2048 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 840					839
Interest rate on long-term debt	4.55%
Senior Unsecured Notes [Member] | 3.700%, due 2049 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 812					812
Interest rate on long-term debt	3.70%
Senior Unsecured Notes [Member] | 3.125% due 2050 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 988					987
Interest rate on long-term debt	3.125%							3.125%
Senior Unsecured Notes [Member] | 3.600% due 2051 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 1,233					1,232
Interest rate on long-term debt	3.60%						3.60%
Senior Unsecured Notes [Member] | 4.550% due 2052 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 689					0
Interest rate on long-term debt	4.55%				4.55%
Senior Unsecured Notes [Member] | 6.100% due 2052 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 741					0
Interest rate on long-term debt	6.10%		6.10%
Senior Unsecured Notes [Member] | 4.850%, due 2054 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 247					247
Interest rate on long-term debt	4.85%
Surplus Notes [Member] | 9.000%, due 2027 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 25					25
Interest rate on long-term debt	9.00%
Senior Convertible Debentures [Member] | 2.750%, due 2042 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 63					72
Interest rate on long-term debt	2.75%								2.75%
Commercial Paper [Member]
Debt Instrument [Line Items]
Commercial paper	$ 0					$ 300