INVESTMENTS (Details 3) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Available-for-sale Securities, Debt Maturities
Total amortized cost	$ 276,952	$ 281,710
Total fair value	275,550	283,753
Minimum contractual maturities of investments with no stated maturities, included as contractual maturities	10 years
Mortgage-backed securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	78	10
After 1 but within 5 years, amortized cost	345	365
After 5 but within 10 years, amortized cost	2,222	1,992
After 10 years, amortized cost	51,821	51,598
Total amortized cost	54,466	53,965
Fair value, due within 1 year	78	10
Fair value, after 1 but within 5 years	353	374
Fair value, after 5 but within 10 years	2,264	2,124
Fair value, after 10 years	51,791	52,963
Total fair value	54,486	55,471
U.S. Treasury and federal agency securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	10,852	9,387
After 1 but within 5 years, amortized cost	66,261	76,454
After 5 but within 10 years, amortized cost	2,036	2,171
After 10 years, amortized cost	2,914	2,669
Total amortized cost	82,063	90,681
Fair value, due within 1 year	10,883	9,499
Fair value, after 1 but within 5 years	66,630	77,267
Fair value, after 5 but within 10 years	2,151	2,408
Fair value, after 10 years	2,941	2,667
Total fair value	82,605	91,841
State and municipal securities
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	1,164	208
After 1 but within 5 years, amortized cost	2,966	3,221
After 5 but within 10 years, amortized cost	375	155
After 10 years, amortized cost	15,439	16,436
Total amortized cost	19,944	20,020
Fair value, due within 1 year	1,165	208
Fair value, after 1 but within 5 years	2,966	3,223
Fair value, after 5 but within 10 years	377	165
Fair value, after 10 years	13,489	14,736
Total fair value	17,997	18,332
Foreign government
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	32,405	34,873
After 1 but within 5 years, amortized cost	52,754	49,587
After 5 but within 10 years, amortized cost	6,288	7,239
After 10 years, amortized cost	972	1,599
Total amortized cost	92,419	93,298
Fair value, due within 1 year	32,360	34,869
Fair value, after 1 but within 5 years	53,159	49,933
Fair value, after 5 but within 10 years	5,722	7,380
Fair value, after 10 years	1,041	1,865
Total fair value	92,282	94,047
All other
Available-for-sale Securities, Debt Maturities
Due within 1 year, amortized cost	2,462	1,001
After 1 but within 5 years, amortized cost	11,070	11,285
After 5 but within 10 years, amortized cost	5,830	4,330
After 10 years, amortized cost	8,698	7,130
Total amortized cost	28,060	23,746
Fair value, due within 1 year	2,402	1,009
Fair value, after 1 but within 5 years	11,189	11,351
Fair value, after 5 but within 10 years	5,871	4,505
Fair value, after 10 years	8,718	7,197
Total fair value	$ 28,180	$ 24,062