BUSINESS COMBINATIONS (Details) (Fuji, AIG Property Casualty) In Millions, except Per Share data, unless otherwise specified	1 Months Ended			12 Months Ended
	Mar. 31, 2011 USD ($)	Mar. 31, 2011 JPY (¥)	Mar. 31, 2010 USD ($)	Dec. 31, 2012	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)
Business Acquisition
Business acquisition, amount of additional voting shares			$ 145
Ownership interest before purchase of additional shares			41.70%
Ownership interest after purchase of additional shares			54.80%	100.00%
Recognized bargain purchase gain on business acquisition						332
Cash tender offer, number of common shares tendered	305	305
Cash tender offer, price per share (in currency per share)	$ 1.76	¥ 146.00
Cash tender offer, purchase price	538
Cash tender offer, purchase price					560
Acquisition of noncontrolling interest					$ 489