Fair Value of Financial Instruments (Carrying and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Assets
Fixed maturity AFS securities		$ 98,050	$ 94,024
Trading securities		3,314	1,950
Equity securities		153	99
Mortgage loans on real estate		13,997	13,260
Derivative investments		981	1,107
Other investments		2,752	2,267
Carrying Value [Member]
Assets
Trading securities		3,314	1,950
Equity securities		153	99
Mortgage loans on real estate		13,997	13,260
Derivative investments	[1]	981	1,107
Other investments		2,740	2,255
Cash and invested cash		1,593	2,345
Separate account assets		143,369	132,833
Future contract benefits:
Indexed annuity and IUL contracts embedded derivatives		(1,730)	(1,305)
Other contract holder funds:
Remaining guaranteed interest and similar contracts		(1,948)	(542)
Account values of certain investment contracts		(35,772)	(34,535)
Short-term debt		(300)
Long-term debt		(5,572)	(5,839)
Reinsurance related embedded derivatives		(177)	(3)
Fair Value [Member]
Assets
Trading securities		3,314	1,950
Equity securities		153	99
Mortgage loans on real estate		13,964	13,092
Derivative investments	[1]	981	1,107
Other investments		2,740	2,255
Cash and invested cash		1,593	2,345
Separate account assets		143,369	132,833
Future contract benefits:
Indexed annuity and IUL contracts embedded derivatives		(1,730)	(1,305)
Other contract holder funds:
Remaining guaranteed interest and similar contracts		(1,948)	(542)
Account values of certain investment contracts		(38,790)	(36,358)
Short-term debt		(309)
Long-term debt		(5,534)	(5,604)
Reinsurance related embedded derivatives		(177)	(3)
Fixed Maturity AFS Securities [Member] | Carrying Value [Member]
Assets
Fixed maturity AFS securities		98,050	94,024
Fixed Maturity AFS Securities [Member] | Fair Value [Member]
Assets
Fixed maturity AFS securities		98,050	94,024
Other Assets [Member] | Carrying Value [Member]
Assets
Other assets - GLB direct embedded derivatives		439	123
Other assets - GLB ceded embedded derivatives		50	72
Indexed annuity ceded embedded derivatives		872	902
Other Assets [Member] | Fair Value [Member]
Assets
Other assets - GLB direct embedded derivatives		439	123
Other assets - GLB ceded embedded derivatives		50	72
Indexed annuity ceded embedded derivatives		872	902
Other Liabilities [Member] | Carrying Value [Member]
Other contract holder funds:
Other liabilities - derivative liabilities	[1]	(242)	(160)
Other Liabilities [Member] | Fair Value [Member]
Other contract holder funds:
Other liabilities - derivative liabilities	[1]	(242)	$ (160)
Other Liabilities [Member] | GLB Ceded Embedded Derivatives [Member] | Carrying Value [Member]
Other contract holder funds:
Other liabilities - GLB embedded derivatives		(8)
Other Liabilities [Member] | GLB Ceded Embedded Derivatives [Member] | Fair Value [Member]
Other contract holder funds:
Other liabilities - GLB embedded derivatives		$ (8)

[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.