Fair Value of Financial Instruments (Fair Value Measured On A Recurring Basis Reconciliation) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018		Mar. 31, 2017
Level 3 Unobservable Input Reconciliation
Beginning Fair Value		$ 3,139		$ 1,545
Items Included in Net Income		540		328
Gains (Losses) in OCI and Other	[1]	(4)		97
Issuances, Sales, Maturities, Settlements, Calls, Net		62		107
Transfers In or Out of Level 3, Net	[2]	(232)	[3]	147
Ending Fair Value		3,505		2,224
Corporate Bonds [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	3,091		2,405
Items Included in Net Income	[4]	3		6
Gains (Losses) in OCI and Other	[1],[4]	17		65
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]	74		(204)
Transfers In or Out of Level 3, Net	[2],[4]	7	[3]	131
Ending Fair Value	[4]	3,192		2,403
ABS [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	27		33
Items Included in Net Income	[4]
Gains (Losses) in OCI and Other	[1],[4]	(1)		1
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]
Transfers In or Out of Level 3, Net	[2],[4]		[3]	(5)
Ending Fair Value	[4]	26		29
U.S. government bonds [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	5
Items Included in Net Income	[4]
Gains (Losses) in OCI and Other	[1],[4]
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]
Transfers In or Out of Level 3, Net	[2],[4]		[3]	5
Ending Fair Value	[4]	5		5
Foreign Government Bonds [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	110		111
Items Included in Net Income	[4]
Gains (Losses) in OCI and Other	[1],[4]	(2)		(1)
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]
Transfers In or Out of Level 3, Net	[2],[3],[4]
Ending Fair Value	[4]	108		110
RMBS [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value		12	[4]	3
Items Included in Net Income			[4]
Gains (Losses) in OCI and Other	[1]		[4]
Issuances, Sales, Maturities, Settlements, Calls, Net			[4]	4
Transfers In or Out of Level 3, Net	[2]	(12)	[3],[4]
Ending Fair Value			[4]	7
CMBS [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	6		7
Items Included in Net Income	[4]	1
Gains (Losses) in OCI and Other	[1],[4]
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]	20		41
Transfers In or Out of Level 3, Net	[2],[4]		[3]	(4)
Ending Fair Value	[4]	27		44
CLOs [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	91		68
Items Included in Net Income	[4]
Gains (Losses) in OCI and Other	[1],[4]
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]	2		5
Transfers In or Out of Level 3, Net	[2],[4]	(91)	[3]	15
Ending Fair Value	[4]	2		88
State and municipal bonds [Member]
Level 3 Unobservable Input Reconciliation
Items Included in Net Income	[4]			(1)
Transfers In or Out of Level 3, Net	[2],[4]			2
Ending Fair Value	[4]			1
Hybrid and redeemable preferred securities [Member] | Fixed maturity AFS securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	76		76
Items Included in Net Income	[4]
Gains (Losses) in OCI and Other	[1],[4]	1		3
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]
Transfers In or Out of Level 3, Net	[2],[3],[4]
Ending Fair Value	[4]	77		79
Equity AFS Securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	162		177
Items Included in Net Income	[4]			1
Gains (Losses) in OCI and Other	[1],[4]			(1)
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]			5
Transfers In or Out of Level 3, Net	[2],[3],[4]	(162)
Ending Fair Value	[4]			182
Trading securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	49		65
Items Included in Net Income	[4]	(2)		1
Gains (Losses) in OCI and Other	[1],[4]			7
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]			(16)
Transfers In or Out of Level 3, Net	[2],[4]		[3]	3
Ending Fair Value	[4]	47		60
Equity Securities [Member]
Level 3 Unobservable Input Reconciliation
Items Included in Net Income	[4]
Gains (Losses) in OCI and Other	[1],[4]
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]	1
Transfers In or Out of Level 3, Net	[2],[3],[4]	26
Ending Fair Value	[4]	27
Derivative investments [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[4]	30		(93)
Items Included in Net Income	[4]	329		(69)
Gains (Losses) in OCI and Other	[1],[4]	(19)		23
Issuances, Sales, Maturities, Settlements, Calls, Net	[4]	(61)		251
Transfers In or Out of Level 3, Net	[2],[3],[4]
Ending Fair Value	[4]	279		112
GLB Direct Embedded Derivatives [Member] | Other assets [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[5]	903
Items Included in Net Income	[5]	207		226
Gains (Losses) in OCI and Other	[1],[5]
Issuances, Sales, Maturities, Settlements, Calls, Net	[5]
Transfers In or Out of Level 3, Net	[2],[3],[5]
Ending Fair Value	[5]	1,110		226
GLB Direct Embedded Derivatives [Member] | Other liabilities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[5]			(371)
Items Included in Net Income	[5]			371
GLB Ceded Embedded Derivatives [Member] | Other assets [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[5]	51		203
Items Included in Net Income	[5]	(6)		(87)
Gains (Losses) in OCI and Other	[1],[5]
Issuances, Sales, Maturities, Settlements, Calls, Net	[5]
Transfers In or Out of Level 3, Net	[2],[3],[5]
Ending Fair Value	[5]	45		116
GLB Ceded Embedded Derivatives [Member] | Other liabilities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[5]	(67)
Items Included in Net Income	[5]	(44)
Gains (Losses) in OCI and Other	[1],[5]
Issuances, Sales, Maturities, Settlements, Calls, Net	[5]
Transfers In or Out of Level 3, Net	[2],[3],[5]
Ending Fair Value	[5]	(111)
Indexed annuity and embedded derivatives [Member] | Other assets [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[5]	11
Items Included in Net Income	[5]
Gains (Losses) in OCI and Other	[1],[5]
Issuances, Sales, Maturities, Settlements, Calls, Net	[5]	6
Transfers In or Out of Level 3, Net	[2],[3],[5]
Ending Fair Value	[5]	17
Indexed annuity and embedded derivatives [Member] | Future contract benefits [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	[5]	(1,418)		(1,139)
Items Included in Net Income	[5]	52		(120)
Gains (Losses) in OCI and Other	[1],[5]
Issuances, Sales, Maturities, Settlements, Calls, Net	[5]	20		21
Transfers In or Out of Level 3, Net	[2],[3],[5]
Ending Fair Value	[5]	$ (1,346)		$ (1,238)

[1] The changes in fair value of the interest rate swaps are offset by an adjustment to derivative investments (see Note 5).

[2] Transfers into or out of Level 3 for AFS and trading securities are displayed at amortized cost as of the beginning-of-year. For AFS and trading securities, the difference between beginning-of-year amortized cost and beginning-of-year fair value was included in OCI and earnings, respectively, in the prior period.

[3] Transfers into or out of Level 3 for FHLB stock between equity securities and other investments at cost on our Consolidated Balance Sheets.

[4] Amortization and accretion of premiums and discounts are included in net investment income on our Consolidated Statements of Comprehensive Income (Loss). Gains (losses) from sales, maturities, settlements and calls and OTTI are included in realized gain (loss) on our Consolidated Statements of Comprehensive Income (Loss).

[5] Gains (losses) from sales, maturities, settlements and calls are included in realized gain (loss) on our Consolidated Statements of Comprehensive Income (Loss).