Fair Value of Assets and Liabilities (Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 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]	$ 290,778	$ 299,090
Equity securities, available-for-sale		9,109	9,861
Total commercial mortgage and other loans	[1]	50,048	46,432
Other long-term investments	[1]	10,591	10,921
Short-term investments		7,937	8,258
Other assets	[1]	14,545	13,379
Separate account assets		280,616	296,435
TOTAL ASSETS		754,527	766,655
Future policy benefits		222,220	217,766
Total liabilities		711,757	724,306
Netting		14,174	12,332
Embedded Derivative, Fair Value Of Embedded Derivative Liability		9,200	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		600	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		9,800	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		290,778	299,090
Trading accounts assets		34,483	31,137
Equity securities, available-for-sale		9,109	9,861
Total commercial mortgage and other loans		151	380
Other long-term investments		1,569	1,772
Short-term investments		7,263	7,735
Cash equivalents		14,630	11,845
Other assets		209	115
Subtotal excluding separate account assets		358,192	361,935
Separate account assets		280,616	296,435
TOTAL ASSETS		638,808	658,370
Future policy benefits		9,173	8,182
Other liabilities		109	228
Notes issued by consolidated VIEs		8,354	6,033
Total liabilities		17,636	14,443
Assets Netting		(14,174)	(12,332)
Liabilities Netting		(5,806)	(6,661)
Netting		8,368	5,671
Fair Value, Measurements, Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(14,164)	(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		(10)	(11)
Fair Value, Measurements, Recurring | Other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities Netting		(5,806)	(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		17,781	20,123
Trading Account Assets - Debt		227	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		8,439	6,531
Trading Account Assets - Debt		189	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		81,806	80,941
Trading Account Assets - Debt		712	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		155,716	160,376
Trading Account Assets - Debt		22,579	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		10,407	11,185
Trading Account Assets - Debt		1,469	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		11,327	13,877
Trading Account Assets - Debt		1,846	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		5,302	6,057
Trading Account Assets - Debt		1,590	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		2,282	2,291
Fair Value, Measurements, Recurring | Other activities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
All other		3,589	1,683
Fair Value, Measurements, Recurring | Other activities | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(14,164)	(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		2,431	1,590
Equity securities, available-for-sale		5,891	6,688
Total commercial mortgage and other loans		0	0
Other long-term investments		10	12
Short-term investments		6,572	5,263
Cash equivalents		3,771	2,657
Other assets		10	4
Subtotal excluding separate account assets		18,685	16,214
Separate account assets		41,140	48,063
TOTAL ASSETS		59,825	64,277
Future policy benefits		0	0
Other liabilities		12	1
Notes issued by consolidated VIEs		0	0
Total liabilities		12	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		1,457	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		974	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		285,278	293,424
Trading accounts assets		44,905	40,648
Equity securities, available-for-sale		2,954	2,898
Total commercial mortgage and other loans		151	380
Other long-term investments		235	224
Short-term investments		691	2,472
Cash equivalents		10,859	9,188
Other assets		183	109
Subtotal excluding separate account assets		345,256	349,343
Separate account assets		212,762	223,710
TOTAL ASSETS		558,018	573,053
Future policy benefits		0	0
Other liabilities		5,901	6,883
Notes issued by consolidated VIEs		0	0
Total liabilities		5,901	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		17,781	20,123
Trading Account Assets - Debt		227	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		8,433	6,525
Trading Account Assets - Debt		189	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		81,685	80,939
Trading Account Assets - Debt		682	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		154,638	159,073
Trading Account Assets - Debt		22,449	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		6,365	7,126
Trading Account Assets - Debt		966	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		11,275	13,834
Trading Account Assets - Debt		1,818	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		5,101	5,804
Trading Account Assets - Debt		1,585	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		215	232
Fair Value, Measurements, Recurring | Level 2 | Other activities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
All other		16,774	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		5,500	5,666
Trading accounts assets		1,311	1,220
Equity securities, available-for-sale		264	275
Total commercial mortgage and other loans		0	0
Other long-term investments		1,334	1,547
Short-term investments		0	0
Cash equivalents		0	0
Other assets		16	2
Subtotal excluding separate account assets		8,425	8,710
Separate account assets		26,714	24,662
TOTAL ASSETS		35,139	33,372
Future policy benefits		9,173	8,182
Other liabilities		2	5
Notes issued by consolidated VIEs		8,354	6,033
Total liabilities		17,529	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		6	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		121	2
Trading Account Assets - Debt		30	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		1,078	1,303
Trading Account Assets - Debt		130	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		4,042	4,059
Trading Account Assets - Debt		503	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		52	43
Trading Account Assets - Debt		28	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		201	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		610	663
Fair Value, Measurements, Recurring | Level 3 | Other activities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
All other		$ 5	$ 7

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