Derivatives and Hedging Activities (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Derivatives and Hedging Activities
Asset	$ 3,069	$ 3,418
Derivatives not designated as hedging instruments
Derivatives and Hedging Activities
Asset	3,069	3,418
Liability	3,669	4,159
Derivatives not designated as hedging instruments | GMWB and GMAB
Derivatives and Hedging Activities
Asset	3,053	3,412
Liability	3,584	4,111
Derivatives not designated as hedging instruments | GMWB and GMAB | Interest rate contracts
Derivatives and Hedging Activities
Asset	1,638	2,191
Liability	1,483	1,486
Derivatives not designated as hedging instruments | GMWB and GMAB | Equity derivatives
Derivatives and Hedging Activities
Asset	1,404	1,215
Liability	2,090	1,792
Derivatives not designated as hedging instruments | GMWB and GMAB | Foreign currency contracts
Derivatives and Hedging Activities
Asset	4	6
Liability	0
Derivatives not designated as hedging instruments | GMWB and GMAB | Embedded derivatives
Derivatives and Hedging Activities
Asset	0
Liability	11	833
Derivatives not designated as hedging instruments | GMWB and GMAB | Credit contracts
Derivatives and Hedging Activities
Asset	7
Derivatives not designated as hedging instruments | EIA embedded derivatives | Equity derivatives
Derivatives and Hedging Activities
Liability	3	2
Derivatives not designated as hedging instruments | IUL | Equity derivatives
Derivatives and Hedging Activities
Asset	16	6
Liability	6	1
Derivatives not designated as hedging instruments | IUL embedded derivatives | Equity derivatives
Derivatives and Hedging Activities
Liability	76	45
Derivatives not designated as hedging instruments | Other derivatives
Derivatives and Hedging Activities
Asset	16	6
Liability	$ 85	$ 48