Segment Information (Total Assets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total assets	$ 841,685	$ 836,781
Latin America [Member]
Segment Reporting Information [Line Items]
Total assets	25,640	23,272
Asia [Member]
Segment Reporting Information [Line Items]
Total assets	124,510	131,138
Europe, the Middle East and Africa [Member]
Segment Reporting Information [Line Items]
Total assets	23,080	23,474
Retail [Member]
Segment Reporting Information [Line Items]
Total assets	342,524	332,387
Group, Voluntary & Worksite Benefits [Member]
Segment Reporting Information [Line Items]
Total assets	45,158	44,138
Corporate Benefit Funding [Member]
Segment Reporting Information [Line Items]
Total assets	227,839	217,352
Corporate & Other [Member]
Segment Reporting Information [Line Items]
Total assets	$ 52,934	$ 65,020