Fair Value of Assets and Liabilities (Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value	[1]	$ 290,063	$ 299,090
Equity securities, available-for-sale		9,901	9,861
Total commercial mortgage and other loans	[1]	48,569	46,432
Other long-term investments	[1]	10,678	10,921
Short-term investments		5,669	8,258
Other assets	[1]	14,728	13,379
Separate account assets		296,341	296,435
TOTAL ASSETS		762,731	766,655
Future policy benefits		216,555	217,766
Total liabilities		720,439	724,306
Netting		9,901	12,332
Embedded Derivative, Fair Value Of Embedded Derivative Liability		5,500	8,200
Gross Asset Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded Derivative, Fair Value Of Embedded Derivative Asset		800	600
Gross Liability Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded Derivative, Fair Value Of Embedded Derivative Liability		6,300	8,800
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		290,063	299,090
Trading accounts assets		33,016	31,137
Equity securities, available-for-sale		9,901	9,861
Total commercial mortgage and other loans		391	380
Other long-term investments		1,944	1,772
Short-term investments		5,124	7,735
Cash equivalents		12,447	11,845
Other assets		115	115
Subtotal excluding separate account assets		353,001	361,935
Separate account assets		296,341	296,435
TOTAL ASSETS		649,342	658,370
Future policy benefits		5,478	8,182
Other liabilities		153	228
Notes Issued by consolidated VIEs		7,434	6,033
Total liabilities		13,065	14,443
Assets Netting		(9,901)	(12,332)
Liabilities Netting		(5,730)	(6,661)
Netting		4,171	5,671
Fair Value, Measurements, Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(9,893)	(12,321)
Fair Value, Measurements, Recurring | Other long-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(8)	(11)
Fair Value, Measurements, Recurring | Other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities Netting		(5,730)	(6,661)
Fair Value, Measurements, Recurring | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		17,811	20,123
Trading Account Assets - Debt		170	399
Fair Value, Measurements, Recurring | Obligations of U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		7,886	6,531
Trading Account Assets - Debt		186	199
Fair Value, Measurements, Recurring | Foreign government bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		78,861	80,941
Trading Account Assets - Debt		708	717
Fair Value, Measurements, Recurring | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		156,574	160,376
Trading Account Assets - Debt		21,816	20,270
Fair Value, Measurements, Recurring | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		11,235	11,185
Trading Account Assets - Debt		1,480	1,243
Fair Value, Measurements, Recurring | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		12,152	13,877
Trading Account Assets - Debt		2,089	2,561
Fair Value, Measurements, Recurring | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		5,544	6,057
Trading Account Assets - Debt		1,598	1,774
Fair Value, Measurements, Recurring | Equity securities, available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		2,408	2,291
Fair Value, Measurements, Recurring | Other activities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
All other		2,561	1,683
Fair Value, Measurements, Recurring | Other activities | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(9,893)	(12,321)
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading accounts assets		1,980	1,590
Equity securities, available-for-sale		6,592	6,688
Total commercial mortgage and other loans		0	0
Other long-term investments		8	12
Short-term investments		4,400	5,263
Cash equivalents		3,809	2,657
Other assets		3	4
Subtotal excluding separate account assets		16,792	16,214
Separate account assets		48,175	48,063
TOTAL ASSETS		64,967	64,277
Future policy benefits		0	0
Other liabilities		(2)	1
Notes Issued by consolidated VIEs		0	0
Total liabilities		(2)	1
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Obligations of U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign government bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Equity securities, available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		1,563	1,396
Fair Value, Measurements, Recurring | Level 1 | Other activities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
All other		417	194
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		284,716	293,424
Trading accounts assets		39,526	40,648
Equity securities, available-for-sale		3,050	2,898
Total commercial mortgage and other loans		391	380
Other long-term investments		230	224
Short-term investments		724	2,472
Cash equivalents		8,638	9,188
Other assets		110	109
Subtotal excluding separate account assets		337,385	349,343
Separate account assets		222,311	223,710
TOTAL ASSETS		559,696	573,053
Future policy benefits		0	0
Other liabilities		5,883	6,883
Notes Issued by consolidated VIEs		0	0
Total liabilities		5,883	6,883
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		17,811	20,123
Trading Account Assets - Debt		170	399
Fair Value, Measurements, Recurring | Level 2 | Obligations of U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		7,866	6,525
Trading Account Assets - Debt		186	199
Fair Value, Measurements, Recurring | Level 2 | Foreign government bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		78,710	80,939
Trading Account Assets - Debt		683	696
Fair Value, Measurements, Recurring | Level 2 | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		155,471	159,073
Trading Account Assets - Debt		21,668	20,146
Fair Value, Measurements, Recurring | Level 2 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		7,418	7,126
Trading Account Assets - Debt		873	850
Fair Value, Measurements, Recurring | Level 2 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		12,111	13,834
Trading Account Assets - Debt		2,087	2,556
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		5,329	5,804
Trading Account Assets - Debt		1,593	1,767
Fair Value, Measurements, Recurring | Level 2 | Equity securities, available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		241	232
Fair Value, Measurements, Recurring | Level 2 | Other activities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
All other		12,025	13,803
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		5,347	5,666
Trading accounts assets		1,403	1,220
Equity securities, available-for-sale		259	275
Total commercial mortgage and other loans		0	0
Other long-term investments		1,714	1,547
Short-term investments		0	0
Cash equivalents		0	0
Other assets		2	2
Subtotal excluding separate account assets		8,725	8,710
Separate account assets		25,855	24,662
TOTAL ASSETS		34,580	33,372
Future policy benefits		5,478	8,182
Other liabilities		2	5
Notes Issued by consolidated VIEs		7,434	6,033
Total liabilities		12,914	14,220
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		0	0
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 3 | Obligations of U.S. states and their political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		20	6
Trading Account Assets - Debt		0	0
Fair Value, Measurements, Recurring | Level 3 | Foreign government bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		151	2
Trading Account Assets - Debt		25	21
Fair Value, Measurements, Recurring | Level 3 | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		1,103	1,303
Trading Account Assets - Debt		148	124
Fair Value, Measurements, Recurring | Level 3 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		3,817	4,059
Trading Account Assets - Debt		607	393
Fair Value, Measurements, Recurring | Level 3 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		41	43
Trading Account Assets - Debt		2	5
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available for-sale, at fair value		215	253
Trading Account Assets - Debt		5	7
Fair Value, Measurements, Recurring | Level 3 | Equity securities, available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		604	663
Fair Value, Measurements, Recurring | Level 3 | Other activities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
All other		$ 12	$ 7

[1] See Note 5 for details of balances associated with variable interest entities.