Segment Information (Total Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total assets	$ 458,218	$ 432,783
Separate account assets	139,335	134,796
Separate account liabilities	139,335	134,796
Retail
Segment Reporting Information [Line Items]
Total assets	180,572	174,853
Separate account assets	59,710	59,217
Separate account liabilities	59,710	59,217
Group, Voluntary & Worksite Benefits
Segment Reporting Information [Line Items]
Total assets	43,161	41,059
Separate account assets	669	644
Separate account liabilities	669	644
Corporate Benefit Funding
Segment Reporting Information [Line Items]
Total assets	205,088	188,960
Separate account assets	78,956	74,935
Separate account liabilities	78,956	74,935
Corporate & Other
Segment Reporting Information [Line Items]
Total assets	29,397	27,911
Separate account assets	0	0
Separate account liabilities	$ 0	$ 0