Short-Term and Long-Term Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Short-term debt	[1]	$ 288	$ 10
Total long-term debt		2,401	2,374
9.76% Surplus Note, Due 2024 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 50	50
Stated interest rate		9.76%
6.56% Surplus Note, Due 2028 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 500	500
Stated interest rate		6.56%
111 bps Surplus Note, Due 2028 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 71	71
111 bps Surplus Note, Due 2028 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Variable rate		1.11%
226 bps Surplus Note, Due 2028 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 600	573
226 bps Surplus Note, Due 2028 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Variable rate		2.26%
6.03% Surplus Note, Due 2028 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 750	750
Stated interest rate		6.03%
200 bps Surplus Note, Due 2035 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 30	30
200 bps Surplus Note, Due 2035 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Variable rate		2.00%
155 bps Surplus Note, Due 2037 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 25	25
155 bps Surplus Note, Due 2037 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Variable rate		1.55%
4.20% Surplus Note, Due 2037 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 50	50
Stated interest rate		4.20%
100 bps Surplus Note, Due 2037 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 312	$ 325
100 bps Surplus Note, Due 2037 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Variable rate		1.00%
4.50% Surplus Note, Due 2038 [Member]
Debt Instrument [Line Items]
Surplus notes		$ 13
Stated interest rate		4.50%

[1] The short-term debt represents short-term notes payable to LNC.