Short-Term and Long-Term Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Current maturities of long-term debt		$ 300
Total short-term debt		300
Total long-term debt		$ 6,067	$ 5,839
Fixed rate, swap		5.00%
Debt repurchase option, Repayment as percent of principal		100.00%
Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes		$ 4,614	4,473
Capital securities		1,213	1,213
Unamortized premiums (discounts)		(4)	(3)
Unamortized debt issuance costs		(34)	(33)
Unamortized adjustments from discontinued hedges		118	123
Fair value hedge on interest rate swap agreements		160	66
Total long-term debt		$ 6,067	5,839
6.25% notes, due 2020 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]		300
Interest rate		6.25%
4.85% notes, due 2021 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 296	300
Interest rate		4.85%
4.20% notes, due 2022 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 300	300
Interest rate		4.20%
LIBOR +100 bps loan, due 2023 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes			200
Variable rate		1.00%
4.00% notes, due 2023 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 500	500
Interest rate		4.00%
LIBOR + 87.5 bps loan, due 2024 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes		$ 250
Variable rate		0.875%
3.35% notes, due 2025 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 300	300
Interest rate		3.35%
3.63% notes, due 2026 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 400	400
Interest rate		3.63%
3.80% notes, due 2028 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 500	500
Interest rate		3.80%
3.05% notes, due 2030 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 500
Interest rate		3.05%
6.15% notes, due 2036 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 243	348
Interest rate		6.15%
6.30% notes, due 2037 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1],[2]	$ 375	375
Interest rate		6.30%
7.00% notes, due 2040 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1],[2]	$ 500	500
Interest rate		7.00%
4.35% notes, due 2048 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Senior Long Term Notes	[1]	$ 450	450
Interest rate		4.35%
LIBOR +236 bps, due 2066 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Capital securities	[3]	$ 722	722
Variable rate		2.36%
LIBOR +204 bps, due 2067 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Capital securities	[3]	$ 491	$ 491
Variable rate		2.04%

[1] We have the option to repurchase the outstanding notes by paying the greater of 100% of the principal amount of the notes to be redeemed or the make-whole amount (as defined in each note agreement), plus in each case any accrued and unpaid interest as of the date of redemption.

[2] Categorized as operating debt for leverage ratio calculations as the proceeds were primarily used as a long-term structured solution to reduce the strain on increasing statutory reserves associated with secondary guarantee UL and term policies.

[3] To hedge the variability in rates, we purchased interest rate swaps to lock in a fixed rate of approximately 5% over the remaining terms of the capital securities.