Debt (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

The Carrying Value Of Long-Term Debt

The carrying value of long-term debt at December 31, 2019 and 2018 consists of the following:

	2019			2018
Senior unsecured notes:
2.250%, due 2019	$	—		$	849
2.500%, due 2020	899			897
4.350%, due 2020	699			688
3.700%, due 2021	699			698
2.950%, due 2022	747			747
3.125%, due 2022	847			846
3.300%, due 2023	1,013			1,000
3.350%, due 2024	846			846
3.500%, due 2024	795			794
2.375%, due 2025	845			—
3.650%, due 2027	1,590			1,589
4.101%, due 2028	1,253			1,250
2.875%, due 2029	819			—
5.950%, due 2034	334			334
5.850%, due 2036	396			396
6.375%, due 2037	366			366
5.800%, due 2040	124			124
4.625%, due 2042	888			887
4.650%, due 2043	987			986
4.650%, due 2044	792			791
5.100%, due 2044	594			594
4.375%, due 2047	1,386			1,386
4.550%, due 2048	838			838
3.700%, due 2049	811			—
4.850%, due 2054	247			247
Surplus note:
9.000%, due 2027	25			25
Senior convertible debentures:
2.750%, due 2042	145			191
Variable rate debt:
Commercial paper program	400			697
Total long-term debt	19,385			18,066
Current portion of long-term debt	(1,598		)	(849		)
Long-term debt, less current portion	$	17,787		$	17,217

Convertible Debenture Terms

The following table summarizes, at December 31, 2019, the related balances, conversion rate and conversion price of the Debentures:

Outstanding principal amount	$	215
Unamortized debt discount	$	68
Net debt carrying amount	$	145
Equity component carrying amount	$	78
Conversion rate (shares of common stock per $1,000 of principal amount)	13.9500
Effective conversion price (per $1,000 of principal amount)	$	71.6843