Investments and Derivative Instruments (Details Textual 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013 Security	Sep. 30, 2012	Sep. 30, 2013 Security	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2012
Carrying value of mortgage loans associated with the valuation allowance	$ 136,000,000		$ 136,000,000			$ 189,000,000
Invested Assets Suppoting Modco	1,300,000,000		1,300,000,000
Net realized capital losses, excluding net OTTI losses recognized in earnings	(25,000,000)	(179,000,000)	(732,000,000)	(701,000,000)
Additional Investments and Derivative Instruments (Textual) [Abstract]
Gross gains and losses on sales and impairments previously reported as unrealized losses in AOCI	(13,000,000)	24,000,000	81,000,000	1,500,000,000
Proceeds from sales of AFS securities	3,500,000,000	7,100,000,000	12,300,000,000	21,300,000,000
Number of securities included in AFS securities in an unrealized loss position, primarily related to municipal securities	1,978		1,978
Percentage of gross unrealized losses depressed	94.00%		94.00%
Securities Depressed to Cost or Amortized Cost Lower Limit	20.00%		20.00%
Minimum maturity of securities included in continuous loss position			10 years
Number of years to maturity for securities concentrated in the financial services sector			10 years
Valuation allowances on mortgage loans held for sale	3,000,000		3,000,000			3,000,000
Mortgage loans held for sale, carrying value	46,000,000		46,000,000			47,000,000
Current weighted average loan to value ratio of commercial mortgage loan	60.00%		60.00%
Original weighted average loan to value ratio of commercial mortgage loan	63.00%		63.00%
Avg. Debt-Service Coverage Ratio	2.27		2.27
Collateral received as percentage of fair value of securities loaned			95.00%
Percent of fair value of securities transferred for collateral obtained on repurchase agreement			at least 95%
Fair value of securities transferred	0		0			1,600,000,000
Agreement to repurchase securities	0		0			1,600,000,000
Gross amount of recognized liability	867,000,000		867,000,000			923,000,000
Financial collateral pledged	883,000,000		883,000,000			923,000,000
Notional amount of interest rate swaps in offsetting relationships	4,500,000,000		4,500,000,000			5,100,000,000
Deferred net gains on derivative instruments before tax to be reclassified to earnings during next twelve months			49,000,000
Maximum amount of net reclassifications from AOCI to earnings				0	0
Commercial [Member]
Financing Receivable Recorded Investment Delinquency Period			90 days or more
Retirement Plans and Individual Life Businesses [Member]
Net realized capital losses, excluding net OTTI losses recognized in earnings			1,500,000,000
Gain (Loss) on Derivative Instruments, Net, Pretax			100,000,000
Commercial [Member]
Carrying value of mortgage loans associated with the valuation allowance	4		4
Valuation Allowance, Amount	$ 1		$ 1
Additional Investments and Derivative Instruments (Textual) [Abstract]
Avg. Debt-Service Coverage Ratio	2.27		2.27			2.34