Fair Values of Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Assets
Available-for-Sale securities: Fixed maturities	$ 24,411	$ 25,932
Common stocks	5	4
Separate account assets	71,828	69,395
Liabilities
Future policy benefits	29,521	30,670
Cumulative decrease to the embedded derivative liability	263	398
Recurring basis | Level 1
Assets
Available-for-Sale securities: Fixed maturities	9	10
Common stocks	2	2
Other assets	326	285
Total assets at fair value	337	297
Liabilities
Other liabilities	269	258
Total liabilities at fair value	269	258
Recurring basis | Level 1 | Equity derivative contracts
Assets
Other assets	326	285
Liabilities
Other liabilities	269	258
Recurring basis | Level 1 | U.S. government and agencies obligations
Assets
Available-for-Sale securities: Fixed maturities	9	10
Recurring basis | Level 2
Assets
Available-for-Sale securities: Fixed maturities	22,476	23,919
Common stocks	3	2
Cash equivalents	213	264
Other assets	2,743	3,133
Separate account assets	71,828	69,395
Total assets at fair value	97,263	96,713
Liabilities
Future policy benefits	3	2
Other liabilities	3,310	3,021
Total liabilities at fair value	3,313	3,023
Recurring basis | Level 2 | Interest rate derivative contracts
Assets
Other assets	1,638	2,191
Liabilities
Other liabilities	1,483	1,486
Recurring basis | Level 2 | Equity derivative contracts
Assets
Other assets	1,094	936
Liabilities
Other liabilities	1,827	1,535
Recurring basis | Level 2 | Foreign currency derivative contracts
Assets
Other assets	4	6
Recurring basis | Level 2 | EIA embedded derivatives
Liabilities
Future policy benefits	3	2
Recurring basis | Level 2 | Credit derivative contracts
Assets
Other assets	7
Recurring basis | Level 2 | Corporate debt securities
Assets
Available-for-Sale securities: Fixed maturities	14,447	15,387
Recurring basis | Level 2 | Residential mortgage backed securities
Assets
Available-for-Sale securities: Fixed maturities	3,555	3,598
Recurring basis | Level 2 | Commercial mortgage backed securities
Assets
Available-for-Sale securities: Fixed maturities	2,457	2,834
Recurring basis | Level 2 | State and municipal obligations
Assets
Available-for-Sale securities: Fixed maturities	1,022	1,122
Recurring basis | Level 2 | Asset backed securities
Assets
Available-for-Sale securities: Fixed maturities	704	715
Recurring basis | Level 2 | Foreign government bonds and obligations
Assets
Available-for-Sale securities: Fixed maturities	254	224
Recurring basis | Level 2 | U.S. government and agencies obligations
Assets
Available-for-Sale securities: Fixed maturities	37	39
Recurring basis | Level 3
Assets
Available-for-Sale securities: Fixed maturities	1,926	2,003
Total assets at fair value	1,926	2,003
Liabilities
Future policy benefits	87	878
Total liabilities at fair value	87	878
Recurring basis | Level 3 | IUL embedded derivatives
Liabilities
Future policy benefits	76	45
Recurring basis | Level 3 | GMWB and GMAB embedded derivatives
Liabilities
Future policy benefits	11	833
Recurring basis | Level 3 | Corporate debt securities
Assets
Available-for-Sale securities: Fixed maturities	1,558	1,654
Recurring basis | Level 3 | Residential mortgage backed securities
Assets
Available-for-Sale securities: Fixed maturities	50	23
Recurring basis | Level 3 | Commercial mortgage backed securities
Assets
Available-for-Sale securities: Fixed maturities	164	170
Recurring basis | Level 3 | Asset backed securities
Assets
Available-for-Sale securities: Fixed maturities	154	156
Recurring basis | Total
Assets
Available-for-Sale securities: Fixed maturities	24,411	25,932
Common stocks	5	4
Cash equivalents	213	264
Other assets	3,069	3,418
Separate account assets	71,828	69,395
Total assets at fair value	99,526	99,013
Liabilities
Future policy benefits	90	880
Other liabilities	3,579	3,279
Total liabilities at fair value	3,669	4,159
Recurring basis | Total | Interest rate derivative contracts
Assets
Other assets	1,638	2,191
Liabilities
Other liabilities	1,483	1,486
Recurring basis | Total | Equity derivative contracts
Assets
Other assets	1,420	1,221
Liabilities
Other liabilities	2,096	1,793
Recurring basis | Total | Foreign currency derivative contracts
Assets
Other assets	4	6
Recurring basis | Total | EIA embedded derivatives
Liabilities
Future policy benefits	3	2
Recurring basis | Total | IUL embedded derivatives
Liabilities
Future policy benefits	76	45
Recurring basis | Total | GMWB and GMAB embedded derivatives
Liabilities
Future policy benefits	11	833
Recurring basis | Total | Credit derivative contracts
Assets
Other assets	7
Recurring basis | Total | Corporate debt securities
Assets
Available-for-Sale securities: Fixed maturities	16,005	17,041
Recurring basis | Total | Residential mortgage backed securities
Assets
Available-for-Sale securities: Fixed maturities	3,605	3,621
Recurring basis | Total | Commercial mortgage backed securities
Assets
Available-for-Sale securities: Fixed maturities	2,621	3,004
Recurring basis | Total | State and municipal obligations
Assets
Available-for-Sale securities: Fixed maturities	1,022	1,122
Recurring basis | Total | Asset backed securities
Assets
Available-for-Sale securities: Fixed maturities	858	871
Recurring basis | Total | Foreign government bonds and obligations
Assets
Available-for-Sale securities: Fixed maturities	254	224
Recurring basis | Total | U.S. government and agencies obligations
Assets
Available-for-Sale securities: Fixed maturities	$ 46	$ 49