Debt (Tables)

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

The Carrying Value Of Long-Term Debt

The carrying value of long-term debt at December 31, 2020 and 2019 consists of the following:

	2020		2019
Senior unsecured notes:
2.500%, due 2020	$	—	$	899
4.350%, due 2020	—		699
3.700%, due 2021	700		699
2.950%, due 2022	749		747
3.125%, due 2022	848		847
3.300%, due 2023	1,027		1,013
3.350%, due 2024	847		846
3.500%, due 2024	796		795
2.375%, due 2025	1,253		845
3.650%, due 2027	1,591		1,590
4.101%, due 2028	1,257		1,253
2.875%, due 2029	819		819
2.250%, due 2030	1,089		—
5.950%, due 2034	334		334
5.850%, due 2036	396		396
6.375%, due 2037	366		366
5.800%, due 2040	114		124
4.625%, due 2042	873		888
4.650%, due 2043	978		987
4.650%, due 2044	779		792
5.100%, due 2044	565		594
4.375%, due 2047	1,387		1,386
4.550%, due 2048	839		838
3.700%, due 2049	811		811
3.125%, due 2050	987		—
4.850%, due 2054	247		247
Surplus note:
9.000%, due 2027	25		25
Senior convertible debentures:
2.750%, due 2042	108		145
Variable rate debt:
Commercial paper program	250		400
Total long-term debt	20,035		19,385
Current portion of long-term debt	(700)		(1,598)
Long-term debt, less current portion	$	19,335	$	17,787

Convertible Debenture Terms

The following table summarizes, at December 31, 2020, the related balances, conversion rate and conversion price of the Debentures:

Outstanding principal amount	$	159
Unamortized debt discount	$	49
Net debt carrying amount	$	108
Equity component carrying amount	$	58
Conversion rate (shares of common stock per $1,000 of principal amount)	14.0808
Effective conversion price (per $1,000 of principal amount)	$	71.0187