Fair Value of Financial Instruments (Carrying and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
AFS securities:
AFS Fixed Maturity Securities		$ 93,161	$ 94,840
Equity securities			246
Trading securities		1,440	1,620
Equity securities		112
Mortgage loans on real estate		12,561	10,762
Derivative investments		706	915
Other investments		2,204	2,296
Carrying Value [Member]
AFS securities:
Equity securities			246
Trading securities		1,440	1,620
Equity securities		112
Mortgage loans on real estate		12,561	10,762
Derivative investments	[1]	706	915
Other investments		2,204	2,296
Cash and invested cash		1,460	1,628
Separate account assets		147,692	144,219
Future contract benefits:
Indexed annuity and IUL contracts embedded derivatives		(1,571)	(1,418)
Other contract holder funds:
Remaining guaranteed interest and similar contracts		(562)	(592)
Account values of certain investment contracts		(33,684)	(32,370)
Short-term debt			(450)
Long-term debt		(5,804)	(4,894)
Reinsurance related embedded derivatives		(20)	(57)
Fair Value [Member]
AFS securities:
Equity securities			246
Trading securities		1,440	1,620
Equity securities		112
Mortgage loans on real estate		12,239	10,877
Derivative investments	[1]	706	915
Other investments		2,204	2,296
Cash and invested cash		1,460	1,628
Separate account assets		147,692	144,219
Future contract benefits:
Indexed annuity and IUL contracts embedded derivatives		(1,571)	(1,418)
Other contract holder funds:
Remaining guaranteed interest and similar contracts		(562)	(592)
Account values of certain investment contracts		(34,577)	(36,200)
Short-term debt			(452)
Long-term debt		(5,795)	(5,042)
Reinsurance related embedded derivatives		(20)	(57)
Fixed Maturity AFS Securities [Member] | Carrying Value [Member]
AFS securities:
AFS Fixed Maturity Securities		93,161	94,840
Fixed Maturity AFS Securities [Member] | Fair Value [Member]
AFS securities:
AFS Fixed Maturity Securities		93,161	94,840
Other Assets [Member] | Carrying Value [Member]
AFS securities:
Other assets - GLB direct embedded derivatives		1,648	903
Other assets - GLB ceded embedded derivatives		35	51
Indexed annuity ceded embedded derivatives		44	11
Other Assets [Member] | Fair Value [Member]
AFS securities:
Other assets - GLB direct embedded derivatives		1,648	903
Other assets - GLB ceded embedded derivatives		35	51
Indexed annuity ceded embedded derivatives		44	11
Other Liabilities [Member] | Carrying Value [Member]
Other contract holder funds:
Other liabilities - derivative liabilities	[1]	(197)	(338)
Other Liabilities [Member] | Fair Value [Member]
Other contract holder funds:
Other liabilities - derivative liabilities	[1]	(197)	(338)
Other Liabilities [Member] | GLB Ceded Embedded Derivatives [Member] | Carrying Value [Member]
Other contract holder funds:
Other liabilities - GLB embedded derivatives		(193)	(67)
Other Liabilities [Member] | GLB Ceded Embedded Derivatives [Member] | Fair Value [Member]
Other contract holder funds:
Other liabilities - GLB embedded derivatives		$ (193)	$ (67)

[1] We have master netting agreements with each of our derivative counterparties, which allow for the netting of our derivative asset and liability positions by counterparty.