Investments (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
U.S. Government and government agencies [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	$ (3)	$ 0
Fair Value - Less than twelve months	60	22
Fair Value as % of Cost - Less than twelve months	95.00%	100.00%
Unrealized Loss - Twelve months or more	0	0
Fair Value - Twelve months or more	0	0
Fair Value as % of Cost - Twelve months or more	0.00%	0.00%
States, municipalities and political subdivisions [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(135)	(5)
Fair Value - Less than twelve months	2,219	285
Fair Value as % of Cost - Less than twelve months	94.00%	98.00%
Unrealized Loss - Twelve months or more	(9)	0
Fair Value - Twelve months or more	73	24
Fair Value as % of Cost - Twelve months or more	89.00%	100.00%
Residential Mortgage Backed Securities [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(9)	(3)
Fair Value - Less than twelve months	553	146
Fair Value as % of Cost - Less than twelve months	98.00%	98.00%
Unrealized Loss - Twelve months or more	(19)	(51)
Fair Value - Twelve months or more	212	411
Fair Value as % of Cost - Twelve months or more	92.00%	89.00%
Commercial Mortgage Backed Securities [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(3)	0
Fair Value - Less than twelve months	106	16
Fair Value as % of Cost - Less than twelve months	97.00%	100.00%
Unrealized Loss - Twelve months or more	0	0
Fair Value - Twelve months or more	2	0
Fair Value as % of Cost - Twelve months or more	100.00%	0.00%
Asset-backed Securities [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(18)	0
Fair Value - Less than twelve months	1,310	146
Fair Value as % of Cost - Less than twelve months	99.00%	100.00%
Unrealized Loss - Twelve months or more	(1)	(2)
Fair Value - Twelve months or more	28	57
Fair Value as % of Cost - Twelve months or more	97.00%	97.00%
All other corporate [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(101)	(3)
Fair Value - Less than twelve months	2,634	237
Fair Value as % of Cost - Less than twelve months	96.00%	99.00%
Unrealized Loss - Twelve months or more	(7)	(2)
Fair Value - Twelve months or more	85	51
Fair Value as % of Cost - Twelve months or more	92.00%	96.00%
Fixed maturities [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(269)	(11)
Fair Value - Less than twelve months	6,882	852
Fair Value as % of Cost - Less than twelve months	96.00%	99.00%
Unrealized Loss - Twelve months or more	(36)	(55)
Fair Value - Twelve months or more	400	543
Fair Value as % of Cost - Twelve months or more	92.00%	91.00%
Common stocks [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(16)	(8)
Fair Value - Less than twelve months	158	88
Fair Value as % of Cost - Less than twelve months	91.00%	92.00%
Unrealized Loss - Twelve months or more	0	0
Fair Value - Twelve months or more	0	0
Fair Value as % of Cost - Twelve months or more	0.00%	0.00%
Perpetual preferred stocks [Member]
Available-for-sale securities in a continuous unrealized loss position
Unrealized Loss - Less than twelve months	(6)	0
Fair Value - Less than twelve months	91	7
Fair Value as % of Cost - Less than twelve months	94.00%	100.00%
Unrealized Loss - Twelve months or more	(4)	(1)
Fair Value - Twelve months or more	$ 20	$ 25
Fair Value as % of Cost - Twelve months or more	83.00%	96.00%