Segment Information (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Revenue from external customers	$ 48,437	$ 46,699	$ 35,427
Life Insurance [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	31,723	30,486	23,978
Accident and Health Insurance [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	13,255	12,269	7,480
Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	3,117	3,043	2,956
Non-Insurance [Member]
Segment Reporting Information [Line Items]
Revenue from external customers	$ 342	$ 901	$ 1,013