INVESTMENTS (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012 Y	Jun. 30, 2011	Jun. 30, 2012 Y	Jun. 30, 2011	Dec. 31, 2011 Y
Available-for-sale Securities, Debt Maturities
Total amortized cost	$ 273,579		$ 273,579		$ 255,656
Total fair value	275,953		275,953		257,019
Minimum contractual maturities of investments with no stated maturities, included as contractual maturities (in years)	10		10		10
Interest and dividends on investments
Taxable interest	1,604	1,834	3,264	3,955
Interest exempt from U.S. federal income tax	166	175	340	396
Dividends	84	117	160	186
Total interest and dividends	1,854	2,126	3,764	4,537
Gross realized investments losses, excluding losses from other-than-temporary impairment
Gross realized investment gains	329	624	2,495	1,304
Gross realized investment losses	(56)	(41)	(297)	(141)
Net realized gains	273	583	2,198	1,163
HTM debt securities
Available-for-sale Securities, Debt Maturities
Carrying value of held-to-maturity investments sold	276		1,243	82
Loss realized on sale of held to maturity securities	25		169	15
Carrying value of securities reclassified as available-for-sale	68		107
Other-than-temporary-impairment loss	13		26
Mortgage-backed securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	17		17
After 1 but within 5 years, amortized cost	266		266		422
After 5 but within 10 years, amortized cost	2,081		2,081		2,757
After 10 years, amortized cost	49,455		49,455		46,470
Total amortized cost	51,819		51,819		49,649
Fair value, due within 1 year	17		17
Fair value, after 1 but within 5 years	268		268		423
Fair value, after 5 but within 10 years	2,174		2,174		2,834
Fair value, after 10 years	50,922		50,922		47,768
Total fair value	53,381		53,381		51,025
U.S. Treasury and federal agency securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	15,763		15,763		14,615
After 1 but within 5 years, amortized cost	66,171		66,171		62,241
After 5 but within 10 years, amortized cost	3,356		3,356		5,862
After 10 years, amortized cost	2,304		2,304		382
Total amortized cost	87,594		87,594		83,100
Fair value, due within 1 year	15,776		15,776		14,637
Fair value, after 1 but within 5 years	67,605		67,605		63,823
Fair value, after 5 but within 10 years	3,706		3,706		6,239
Fair value, after 10 years	2,385		2,385		439
Total fair value	89,472		89,472		85,138
State and municipal securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	71		71		142
After 1 but within 5 years, amortized cost	2,531		2,531		455
After 5 but within 10 years, amortized cost	195		195		182
After 10 years, amortized cost	15,860		15,860		16,040
Total amortized cost	18,657		18,657		16,819
Fair value, due within 1 year	72		72		142
Fair value, after 1 but within 5 years	2,534		2,534		457
Fair value, after 5 but within 10 years	383		383		188
Fair value, after 10 years	13,724		13,724		13,612
Total fair value	16,713		16,713		14,399
Foreign government
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	38,722		38,722		34,924
After 1 but within 5 years, amortized cost	47,905		47,905		41,612
After 5 but within 10 years, amortized cost	7,286		7,286		6,993
After 10 years, amortized cost	1,058		1,058		831
Total amortized cost	94,971		94,971		84,360
Fair value, due within 1 year	38,742		38,742		34,864
Fair value, after 1 but within 5 years	48,209		48,209		41,675
Fair value, after 5 but within 10 years	7,396		7,396		6,998
Fair value, after 10 years	1,225		1,225		977
Total fair value	95,572		95,572		84,514
All other
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	1,434		1,434		4,055
After 1 but within 5 years, amortized cost	10,503		10,503		9,843
After 5 but within 10 years, amortized cost	3,346		3,346		3,009
After 10 years, amortized cost	5,255		5,255		4,821
Total amortized cost	20,538		20,538		21,728
Fair value, due within 1 year	1,431		1,431		4,072
Fair value, after 1 but within 5 years	10,634		10,634		9,928
Fair value, after 5 but within 10 years	3,487		3,487		3,160
Fair value, after 10 years	5,263		5,263		4,783
Total fair value	$ 20,815		$ 20,815		$ 21,943