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, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:	[1]	$ 332,270	$ 290,323
Equity securities, available-for-sale		9,496	9,274
Commercial mortgage and other loans	[1]	51,447	50,559
Other long-term investments	[1]	10,247	9,986
Short-term investments		5,035	8,105
Other assets	[1],[2]	14,322	14,225
Separate account assets		284,832	285,570
TOTAL ASSETS		796,490	757,255
Future policy benefits		242,950	224,384
Total liabilities		741,312	715,332
Netting		21,707	11,457
Embedded Derivative, Fair Value Of Embedded Derivative Liability		13,300	8,400
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	700
Gross Liability Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded Derivative, Fair Value Of Embedded Derivative Liability		14,100	9,100
U.S. corporate private securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Under Set Off Arrangements		1,127	1,039
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		332,270	290,323
Trading accounts assets		28,970	34,980
Equity securities, available-for-sale		9,496	9,274
Commercial mortgage and other loans		591	274
Other long-term investments		100	182
Short-term investments		4,355	7,487
Cash equivalents		19,705	14,208
Other assets		65	16
Subtotal excluding separate account assets		395,552	356,744
Separate account assets		259,093	259,909
TOTAL ASSETS		654,645	616,653
Future policy benefits		13,328	8,434
Other liabilities		1,102	33
Notes issued by consolidated VIEs		2,094	8,597
Total liabilities		16,524	17,064
Assets Netting		(21,707)	(11,457)
Liabilities Netting		(7,849)	(5,276)
Netting		13,858	6,181
Fair Value, Measurements, Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(21,693)	(11,447)
Fair Value, Measurements, Recurring | Other long-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(14)	(10)
Fair Value, Measurements, Recurring | Other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities Netting		(7,849)	(5,276)
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:		22,429	18,517
Trading account assets - debt		384	288
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:		9,779	8,795
Trading account assets - debt		209	189
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:		105,987	83,713
Trading account assets - debt		894	731
Fair Value, Measurements, Recurring | U.S. corporate public securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		85,430	75,368
Fair Value, Measurements, Recurring | U.S. corporate private securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		31,565	30,444
Fair Value, Measurements, Recurring | Foreign Corporate Public Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		30,136	28,554
Fair Value, Measurements, Recurring | Foreign Corporate Private Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		20,337	19,138
Fair Value, Measurements, Recurring | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets - debt		17,616	23,328
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:		10,187	10,226
Trading account assets - debt		1,414	1,345
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:		11,643	10,462
Trading account assets - debt		1,995	1,873
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:		4,777	5,106
Trading account assets - debt		1,403	1,513
Fair Value, Measurements, Recurring | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		2,267	2,352
Fair Value, Measurements, Recurring | All other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets - All other		2,788	3,361
Fair Value, Measurements, Recurring | All other | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Netting		(21,693)	(11,447)
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		0	0
Trading accounts assets		1,586	2,172
Equity securities, available-for-sale		5,939	6,011
Commercial mortgage and other loans		0	0
Other long-term investments		3	13
Short-term investments		2,926	6,776
Cash equivalents		5,941	4,834
Other assets		0	0
Subtotal excluding separate account assets		16,395	19,806
Separate account assets		37,484	43,076
TOTAL ASSETS		53,879	62,882
Future policy benefits		0	0
Other liabilities		66	1
Notes issued by consolidated VIEs		0	0
Total liabilities		66	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:		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:		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:		0	0
Trading account assets - debt		7	0
Fair Value, Measurements, Recurring | Level 1 | U.S. corporate public securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. corporate private securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign Corporate Public Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign Corporate Private Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		0	0
Fair Value, Measurements, Recurring | Level 1 | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
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:		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:		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:		0	0
Trading account assets - debt		0	0
Fair Value, Measurements, Recurring | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		1,470	1,542
Fair Value, Measurements, Recurring | Level 1 | All other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets - All other		109	630
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		326,620	284,703
Trading accounts assets		47,926	42,821
Equity securities, available-for-sale		3,256	2,997
Commercial mortgage and other loans		591	274
Other long-term investments		97	130
Short-term investments		1,429	711
Cash equivalents		13,764	9,374
Other assets		3	9
Subtotal excluding separate account assets		393,686	341,019
Separate account assets		219,481	214,838
TOTAL ASSETS		613,167	555,857
Future policy benefits		0	0
Other liabilities		8,883	5,306
Notes issued by consolidated VIEs		0	0
Total liabilities		8,883	5,306
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:		22,429	18,517
Trading account assets - debt		384	288
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:		9,774	8,789
Trading account assets - debt		209	189
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:		105,863	83,590
Trading account assets - debt		849	697
Fair Value, Measurements, Recurring | Level 2 | U.S. corporate public securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		85,219	75,163
Fair Value, Measurements, Recurring | Level 2 | U.S. corporate private securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		30,309	29,750
Fair Value, Measurements, Recurring | Level 2 | Foreign Corporate Public Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		30,044	28,510
Fair Value, Measurements, Recurring | Level 2 | Foreign Corporate Private Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		19,642	18,859
Fair Value, Measurements, Recurring | Level 2 | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets - debt		17,400	23,125
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:		7,106	6,178
Trading account assets - debt		1,109	749
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:		11,640	10,424
Trading account assets - debt		1,994	1,870
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:		4,594	4,923
Trading account assets - debt		1,399	1,509
Fair Value, Measurements, Recurring | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		212	221
Fair Value, Measurements, Recurring | Level 2 | All other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets - All other		24,370	14,173
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		5,650	5,620
Trading accounts assets		1,151	1,434
Equity securities, available-for-sale		301	266
Commercial mortgage and other loans		0	0
Other long-term investments		14	49
Short-term investments		0	0
Cash equivalents		0	0
Other assets		62	7
Subtotal excluding separate account assets		7,178	7,376
Separate account assets		2,128	1,995
TOTAL ASSETS		9,306	9,371
Future policy benefits		13,328	8,434
Other liabilities		2	2
Notes issued by consolidated VIEs		2,094	8,597
Total liabilities		15,424	17,033
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:		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:		5	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:		124	123
Trading account assets - debt		38	34
Fair Value, Measurements, Recurring | Level 3 | U.S. corporate public securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		211	205
Fair Value, Measurements, Recurring | Level 3 | U.S. corporate private securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		1,256	694
Fair Value, Measurements, Recurring | Level 3 | Foreign Corporate Public Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		92	44
Fair Value, Measurements, Recurring | Level 3 | Foreign Corporate Private Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale:		695	279
Fair Value, Measurements, Recurring | Level 3 | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets - debt		216	203
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:		3,081	4,048
Trading account assets - debt		305	596
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:		3	38
Trading account assets - debt		1	3
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:		183	183
Trading account assets - debt		4	4
Fair Value, Measurements, Recurring | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		585	589
Fair Value, Measurements, Recurring | Level 3 | All other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets - All other		$ 2	$ 5

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

[2] Prior period amounts are presented on a basis consistent with the current period presentation, reflecting the adoption of ASU 2015-03. See Note 2 for additional information.