Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pre-tax
Unrealized net holding gains and losses arising during the period, net of related offsets, Pre-tax	$ 322	$ (1,559)	$ 1,039	$ (1,361)
Less: reclassification adjustment of realized capital gains and losses, Pre-tax	232	369	265	458
Unrealized net capital gains and losses, Pre-tax	90	(1,928)	774	(1,819)
Unrecognized pension and other postretirement benefit cost arising during the period, Pre-tax	(4)	7		9
Less: reclassification adjustment of net periodic cost recognized in operating costs and expenses, Pre-tax	(15)	(64)	(28)	(130)
Unrecognized pension and other postretirement benefit cost, Pre-tax	11	71	28	139
Unrealized foreign currency translation adjustments, Pre-tax	20	(33)	(5)	(51)
Other comprehensive income (loss), Pre-tax	121	(1,890)	797	(1,731)
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets, Tax	(112)	545	(363)	476
Less: reclassification adjustment of realized capital gains and losses, Tax	(81)	(129)	(93)	(160)
Unrealized net capital gains and losses, Tax	(31)	674	(270)	636
Unrecognized pension and other postretirement benefit cost arising during the period, Tax	2	(2)	1	(2)
Less: reclassification adjustment of net periodic cost recognized in operating costs and expenses, Tax	5	23	10	46
Unrecognized pension and other postretirement benefit cost, Tax	(3)	(25)	(9)	(48)
Unrealized foreign currency translation adjustments, Tax	(7)	12	2	18
Other comprehensive income (loss), Tax	(41)	661	(277)	606
After-tax
Unrealized net holding gains and losses arising during the period, net of related offsets, After-tax	210	(1,014)	676	(885)
Less: reclassification adjustment of realized capital gains and losses, After-tax	151	240	172	298
Unrealized net capital gains and losses, After-tax	59	(1,254)	504	(1,183)
Unrecognized pension and other postretirement benefit cost arising during the period, After-tax	(2)	5	1	7
Less: reclassification adjustment of net periodic cost recognized in operating costs and expenses, After-tax	(10)	(41)	(18)	(84)
Unrecognized pension and other postretirement benefit cost, After-tax	8	46	19	91
Unrealized foreign currency translation adjustments, After-tax	13	(21)	(3)	(33)
Other comprehensive income (loss), after-tax	80	(1,229)	520	(1,125)
Net income	645	434	1,245	1,143
Comprehensive income (loss)	$ 725	$ (795)	$ 1,765	$ 18