INVESTMENTS (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Available-for-sale Securities, Debt Maturities
Total amortized cost	$ 264,582		$ 264,582		$ 255,656
Total fair value	267,651		267,651		257,019
Minimum contractual maturities of investments with no stated maturities, included as contractual maturities			10 years		10 years
Available-for-sale Securities transferred from Held-to-maturity
Carrying value of available-for-sale investments sold transferred from held-to-maturity	302		1,545	1,067
Loss realized on sale of available-for-sale investments sold transferred from held-to-maturity	4		173	138
Carrying value of securities reclassified as available-for-sale	137		244
Other-than-temporary impairment loss recorded for available-for-sale investments transferred from held-to-maturity	33		59
Interest and dividends on investments
Taxable interest	1,636	1,694	4,900	5,649
Interest exempt from U.S. federal income tax	168	173	508	569
Dividends	78	57	238	243
Total interest and dividends	1,882	1,924	5,646	6,461
Gross realized investments losses, excluding losses from other-than-temporary impairment
Gross realized investment gains	660	920	3,155	2,224
Gross realized investment losses	(45)	(155)	(342)	(296)
Net realized gains	615	765	2,813	1,928
Mortgage-backed securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	21		21
After 1 but within 5 years, amortized cost	287		287		422
After 5 but within 10 years, amortized cost	2,418		2,418		2,757
After 10 years, amortized cost	47,636		47,636		46,470
Total amortized cost	50,362		50,362		49,649
Fair value, due within 1 year	22		22
Fair value, after 1 but within 5 years	289		289		423
Fair value, after 5 but within 10 years	2,548		2,548		2,834
Fair value, after 10 years	49,385		49,385		47,768
Total fair value	52,244		52,244		51,025
U.S. Treasury and federal agency securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	7,358		7,358		14,615
After 1 but within 5 years, amortized cost	69,323		69,323		62,241
After 5 but within 10 years, amortized cost	2,899		2,899		5,862
After 10 years, amortized cost	2,965		2,965		382
Total amortized cost	82,545		82,545		83,100
Fair value, due within 1 year	7,359		7,359		14,637
Fair value, after 1 but within 5 years	70,867		70,867		63,823
Fair value, after 5 but within 10 years	3,167		3,167		6,239
Fair value, after 10 years	3,015		3,015		439
Total fair value	84,408		84,408		85,138
State and municipal securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	201		201		142
After 1 but within 5 years, amortized cost	2,888		2,888		455
After 5 but within 10 years, amortized cost	249		249		182
After 10 years, amortized cost	16,437		16,437		16,040
Total amortized cost	19,775		19,775		16,819
Fair value, due within 1 year	201		201		142
Fair value, after 1 but within 5 years	2,891		2,891		457
Fair value, after 5 but within 10 years	445		445		188
Fair value, after 10 years	14,566		14,566		13,612
Total fair value	18,103		18,103		14,399
Foreign government
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	37,139		37,139		34,924
After 1 but within 5 years, amortized cost	45,261		45,261		41,612
After 5 but within 10 years, amortized cost	7,060		7,060		6,993
After 10 years, amortized cost	898		898		831
Total amortized cost	90,358		90,358		84,360
Fair value, due within 1 year	37,149		37,149		34,864
Fair value, after 1 but within 5 years	45,627		45,627		41,675
Fair value, after 5 but within 10 years	7,191		7,191		6,998
Fair value, after 10 years	1,097		1,097		977
Total fair value	91,064		91,064		84,514
All other
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	1,319		1,319		4,055
After 1 but within 5 years, amortized cost	10,890		10,890		9,843
After 5 but within 10 years, amortized cost	3,419		3,419		3,009
After 10 years, amortized cost	5,914		5,914		4,821
Total amortized cost	21,542		21,542		21,728
Fair value, due within 1 year	1,327		1,327		4,072
Fair value, after 1 but within 5 years	10,947		10,947		9,928
Fair value, after 5 but within 10 years	3,598		3,598		3,160
Fair value, after 10 years	5,960		5,960		4,783
Total fair value	$ 21,832		$ 21,832		$ 21,943