PREFERRED STOCK (Details) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended		3 Months Ended		0 Months Ended	6 Months Ended	12 Months Ended	0 Months Ended	6 Months Ended	12 Months Ended	0 Months Ended	6 Months Ended	12 Months Ended	0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2013 Forecast	Sep. 30, 2013 Forecast	Jan. 25, 2008 Series AA	Jun. 30, 2013 Series AA	Dec. 31, 2012 Series AA	Oct. 29, 2012 Series A	Jun. 30, 2013 Series A	Dec. 31, 2012 Series A	Dec. 13, 2012 Series B	Jun. 30, 2013 Series B	Dec. 31, 2012 Series B	Mar. 26, 2013 Series C	Jun. 30, 2013 Series C	Apr. 30, 2013 Series D	Jun. 30, 2013 Series D	Apr. 28, 2008 Series E	Jun. 30, 2013 Series E	Dec. 31, 2012 Series E	Dec. 31, 2012 Series F	Dec. 31, 2012 Series T
Preferred stock
Dividend rate (as a percent)						8.125%	8.125%		5.95%	5.95%		5.90%	5.90%		5.80%		5.35%		8.40%	8.40%	8.50%	6.50%
Redemption price per depositary share/ preference share (in dollars per share)						$ 25	$ 25		$ 1,000	$ 1,000		$ 1,000	$ 1,000		$ 25		$ 1,000		$ 1,000	$ 1,000	$ 25	$ 50
Number of depositary shares						3,870,330	3,870,330		1,500,000	1,500,000		750,000	750,000		23,000,000		1,250,000		121,254	121,254	2,863,369	453,981
Carrying value	$ 4,293	$ 2,562				$ 97	$ 97		$ 1,500	$ 1,500		$ 750	$ 750		$ 575		$ 1,250		$ 121	$ 121	$ 71	$ 23
Depositary shares interest in shares of preferred stock					0.001			0.04			0.04			0.001		0.04		0.04
Dividend per depositary shares (in dollars per share)					$ 0.51													$ 42.70
Period following the Regulatory Capital Event, the preferred stock may be redeemed in full but not in part														90 days		90 days
Period over which dividend is payable semi-annually																		10 years
Distribution of preferred dividends	$ 13		$ 52	$ 110