Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total assets	$ 898,409	$ 902,337
Retail
Segment Reporting Information [Line Items]
Total assets	357,228	359,188
Group, Voluntary & Worksite Benefits
Segment Reporting Information [Line Items]
Total assets	46,395	46,483
Corporate Benefit Funding
Segment Reporting Information [Line Items]
Total assets	231,739	228,543
Latin America
Segment Reporting Information [Line Items]
Total assets	70,541	72,259
Asia
Segment Reporting Information [Line Items]
Total assets	113,676	117,894
Europe, the Middle East and Africa
Segment Reporting Information [Line Items]
Total assets	28,472	29,217
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	$ 50,358	$ 48,753