Investments and Derivative Instruments Level 4 Available-for-Sale Securities (Details) $ in Millions		Dec. 31, 2015 USD ($) securities		Dec. 31, 2014 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		$ 56,965		$ 55,362
Available-for-sale Equity Securities, Amortized Cost Basis		1,135		1,027
Available-for-sale Securities, Amortized Cost Basis		57,807		56,038
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		2,892		4,377
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		2,930		4,427
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(658)		(358)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax		699		385
Available-for-sale Securities, Debt Securities		59,196		59,384
Available-for-sale Securities, Equity Securities		1,121		1,047
Available-for-sale Securities				60,083
Investments Classified by Contractual Maturity Date [Abstract]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis		2,373		2,141
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value		2,405		2,168
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis		10,929		11,264
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value		11,200		11,827
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis		9,322		8,802
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value		9,497		9,226
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis		20,178		19,859
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value		21,794		22,517
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis		14,163		13,296
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value		14,300		13,646
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		19,095		6,318
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		18,569		6,174
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		526		144
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		3,072		4,667
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		2,896		4,429
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		173		241
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		22,167		10,985
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		21,465		10,603
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		$ 699		385
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities		4,850
Percentage of Gross Unrealized Losses Depressed Less than Twenty Percent of Cost or Amortized Cost		91.00%
Fixed maturities available-for-sale, excluding mortgage-backed and asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		$ 42,802		42,066
Available-for-sale Securities, Debt Securities		44,896		45,738
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		2,520		2,470
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		24		39
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(45)		(37)
Available-for-sale Securities, Debt Securities		2,499		2,472
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	0		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		1,619		897
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,609		893
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		10		4
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		357		473
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		322		440
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		35		33
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		1,976		1,370
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		1,931		1,333
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		45		37
Collateralized Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		2,989		2,776
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		75		98
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(23)		(36)
Available-for-sale Securities, Debt Securities		3,038		2,841
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1],[2]	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		1,164	[3]	748	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,154	[3]	743	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		10	[3]	5	[4]
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		1,243	[3]	1,489	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		1,227	[3]	1,461	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		13	[3]	31	[4]
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		2,407	[3]	2,237	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		2,381	[3]	2,204	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		23	[3]	36	[4]
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		4,668		4,235
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		105		196
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(56)		(16)
Available-for-sale Securities, Debt Securities		4,717		4,415
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	8		6
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		1,726		230
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,681		227
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		45		3
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		189		319
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		178		306
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		11		13
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		1,915		549
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		1,859		533
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		56		16
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		25,876		25,188
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		1,342		2,382
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(416)		(211)
Available-for-sale Securities, Debt Securities		26,802		27,359
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	3		3
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		9,206		3,082
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		8,866		2,980
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		340		102
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		656		1,177
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		580		1,068
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		76		109
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		9,862		4,259
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		9,446		4,048
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		416		211
Foreign Government Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		1,321		1,592
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		34		73
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(47)		(29)
Available-for-sale Securities, Debt Securities		1,308		1,636
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		679		363
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		646		349
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		33		14
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		124		227
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		110		212
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		14		15
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		803		590
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		756		561
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		47		29
Municipal Bonds [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		440		74
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		430		73
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		10		1
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		18		86
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		17		82
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		1		4
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		458		160
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		447		155
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		11		5
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		11,124		11,735
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		1,008		1,141
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(11)		(5)
Available-for-sale Securities, Debt Securities		12,121		12,871
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	0		0
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		3,986		3,815
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		82		122
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(22)		(19)
Available-for-sale Securities, Debt Securities		4,046		3,918
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	0		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		1,349		320
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,340		318
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		9		2
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		415		433
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		402		416
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		13		17
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		1,764		753
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		1,742		734
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		22		19
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		4,481		3,551
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		222		326
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		(38)		(5)
Available-for-sale Securities, Debt Securities		4,665		3,872
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		2,432		432
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		2,394		431
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		38		1
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		8		361
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		8		357
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		0		4
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		2,440		793
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		2,402		788
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		38		5
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	11		11
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost		18,615		6,146
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		18,120		6,014
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		495		132
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost		3,010		4,565
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		2,844		4,342
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		163		226
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost		21,625		10,711
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		20,964		10,356
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss		658		358
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis		842		676
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax		38		50
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax		(41)		(27)
Available-for-sale Securities, Equity Securities		839		699
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1],[5]	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Amortized Cost	[4]	480		172
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	[4]	449		160
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[4]	31		12
Available-for-sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Amortized Cost	[4]	62		102
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	[4]	52		87
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	[4]	10		15
Available-for-sale Securities Continuous Unrealized Loss Position Amortized Cost	[4]	542		274
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	[4]	501		247
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	[4]	41		27
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities		60,035
Accumulated Other Comprehensive Income (Loss), Other than Temporary Impairment, Not Credit Loss, Net of Tax, Available-for-sale, Debt Securities	[1]	11		11
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis		293		351
Available-for-sale Securities, Equity Securities		282		$ 348
Fixed Maturities [Member]
Available-for-sale Securities Pledged as Collateral for Parenthetical Disclosure [Abstract]
Available-for-sale Securities Pledged as Collateral		440
Cash [Member]
Available-for-sale Securities Pledged as Collateral for Parenthetical Disclosure [Abstract]
Available-for-sale Securities Pledged as Collateral		$ 5

[1] Represents the amount of cumulative non-credit OTTI losses recognized in OCI on securities that also had credit impairments. These losses are included in gross unrealized losses as of December 31, 2015 and 2014.

[2] Gross unrealized gains (losses) exclude the fair value of bifurcated embedded derivatives within certain securities. Subsequent changes in value are recorded in net realized capital gains (losses).

[3] Unrealized losses exclude the change in fair value of bifurcated embedded derivatives within certain securities, for which changes in fair value are recorded in net realized capital gains (losses).

[4] As of December 31, 2015 and 2014, excludes equity securities, FVO which are included in equity securities, AFS on the Consolidated Balance Sheets.

[5] Excludes equity securities, FVO with a cost and fair value of $293 and $282, respectively, as of December 31, 2015, and $351 and $348 as of December 31, 2014.