Pension and Other Postretirement Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amounts Recognized in Accumulated OCI, Net of Tax
Net amount recognized	$ (32,000,000)	$ (97,000,000)	$ 29,000,000
Health care cost trend rate [Abstract]
Expected pre-65 health care cost trend rate, for next year	8.00%
Expected post-65 health care cost trend rate, for next year	8.00%
Domestic Equity Allocation U S Plan Employees	35.00%
Domestic Equity Allocation Small Cap U S Plan Employees	5.00%
Domestic Equity Allocation Large Cap U S Plan Employees	25.00%
Domestic Equity Allocation Hedge Fund U S Plan Employees	5.00%
Domestic Equity Allocation U S Plan Agents	14.00%
Domestic Equity Allocation Large Cap U S Plan Agents	10.00%
Domestic Equity Allocation Small Cap U S Plan Agents	2.00%
Domestic Equity Allocation Hedge Funds U S Plan Agents	2.00%
Expected pension plans expense [Abstract]
Expected U.S. pension plans expense, for next year	2,000,000
Expected U.K. pension plan expense, for next year	1,000,000
Average pounds sterling to U.S. dollar exchange rate used to determine expected U.K. pension plan expense, for next year	1.62
Estimated amount of amortization from accumulated OCI into net periodic benefit expense [Abstract]
Estimated amount of amortization from accumulated OCI into net periodic benefit expense, next year	(26,000,000)
Pension and Other Postretirement Benefit Contributions [Abstract]
Pension Contributions	25,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	10,000,000
Invested cash [Member]
Pension plan target allocations by asset category [Abstract]
Other assets	2.00%	1.00%
Invested cash [Member] | Employees Plans [Member]
Pension plan target allocations by asset category [Abstract]
Other assets	0.00%	0.00%
Invested cash [Member] | Agents Plans [Member]
Pension plan target allocations by asset category [Abstract]
Other assets	0.00%	0.00%
U.S. pension plan assets [Member]
Change in Plan Assets
Fair value as of beginning-of-year	956,000,000	918,000,000
Actual return on plan assets	123,000,000	72,000,000
Company and participant contributions	32,000,000	36,000,000
Benefits paid	(68,000,000)	(70,000,000)
Medicare Part D subsidy	0	0
Foreign exchange translation	0	0
Fair value as of end-of-year	1,043,000,000	956,000,000	918,000,000
Amounts Recognized on the Consolidated Balance Sheets
Other assets	21,000,000	18,000,000
Other liabilities	(262,000,000)	(300,000,000)
Net amount recognized	(241,000,000)	(282,000,000)
Amounts Recognized in Accumulated OCI, Net of Tax
Net (gain) loss	229,000,000	243,000,000
Prior service credit	0	0
Net amount recognized	229,000,000	243,000,000
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate used in calculating benefit obligations	4.16%	4.45%
Expected return on plan assets used in calculating benefit obligations	7.79%	7.78%
Weighted-Average Assumptions, Net periodic benefit cost:
Weighted-average discount rate used in calculating net periodic benefit cost	4.45%	5.45%
Expected return on plan assets used in calculating net periodic benefit cost	7.79%	7.78%
Assumptions, next year [Abstract]
Discount rate, assumed for next year	4.16%
Expected return on plan assets, assumed for next year	7.79%
Accumulated benefit obligation in excess of plan assets [Abstract]
Accumulated benefit obligation	1,160,000,000	1,118,000,000
Projected benefit obligation	1,160,000,000	1,118,000,000
Fair value of plan assets	898,000,000	818,000,000
Components of net defined benefit pension plan and postretirement benefit plan expense [Abstract]
Service cost	(5,000,000)	(3,000,000)	3,000,000
Interest cost	(53,000,000)	(58,000,000)	61,000,000
Expected return on plan assets	(72,000,000)	(71,000,000)	(65,000,000)
Amortization of prior service cost	0	0	0
Recognized net actuarial loss (gain)	26,000,000	13,000,000	15,000,000
Net periodic benefit expense (recovery)	12,000,000	3,000,000	14,000,000
U.S. pension plan assets [Member] | Available-for-sale fixed maturity securities [Member] | Employees Plans [Member]
Pension plan target allocations by asset category [Abstract]
Debt securities	50.00%	50.00%
U.S. pension plan assets [Member] | Available-for-sale fixed maturity securities [Member] | Agents Plans [Member]
Pension plan target allocations by asset category [Abstract]
Debt securities	80.00%	80.00%
U.S. pension plan assets [Member] | Corporate bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	343,000,000	370,000,000
U.S. pension plan assets [Member] | U.S. government bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	186,000,000	114,000,000
U.S. pension plan assets [Member] | Foreign government bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	16,000,000	24,000,000
U.S. pension plan assets [Member] | CMBS [Member]
Change in Plan Assets
Fair value as of end-of-year	3,000,000	4,000,000
U.S. pension plan assets [Member] | Equity securities [Member] | Employees Plans [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	0.00%	0.00%
U.S. pension plan assets [Member] | Equity securities [Member] | Agents Plans [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	0.00%	0.00%
U.S. pension plan assets [Member] | Common stock [Member]
Change in Plan Assets
Fair value as of end-of-year	475,000,000	418,000,000
U.S. pension plan assets [Member] | Common Stock Domestic Large Cap Equity [Member] | Employees Plans [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	35.00%	35.00%
U.S. pension plan assets [Member] | Common Stock Domestic Large Cap Equity [Member] | Agents Plans [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	14.00%	14.00%
U.S. pension plan assets [Member] | Common Stock International Equity [Member] | Employees Plans [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	15.00%	15.00%
U.S. pension plan assets [Member] | Common Stock International Equity [Member] | Agents Plans [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	6.00%	6.00%
U.S. pension plan assets [Member] | Invested cash [Member]
Change in Plan Assets
Fair value as of end-of-year	18,000,000	24,000,000
U.S. pension plan assets [Member] | RMBS [Member]
Change in Plan Assets
Fair value as of end-of-year	1,000,000	1,000,000
U.S. pension plan assets [Member] | CDOs [Member]
Change in Plan Assets
Fair value as of end-of-year	1,000,000	1,000,000
U.S. pension plan assets [Member] | Qualified Plans [Member]
Estimated future benefit payments [Abstract]
2013	74,000,000
2014	71,000,000
2015	70,000,000
2016	71,000,000
2017	70,000,000
Following five years thereafter	340,000,000
U.S. pension plan assets [Member] | Nonqualified Plans [Member]
Estimated future benefit payments [Abstract]
2013	10,000,000
2014	10,000,000
2015	12,000,000
2016	10,000,000
2017	9,000,000
Following five years thereafter	45,000,000
Non-U.S. Pension Benefits [Member]
Change in Plan Assets
Fair value as of beginning-of-year	350,000,000	314,000,000
Actual return on plan assets	28,000,000	49,000,000
Company and participant contributions	7,000,000	1,000,000
Benefits paid	(14,000,000)	(12,000,000)
Medicare Part D subsidy	0	0
Foreign exchange translation	0	(2,000,000)
Fair value as of end-of-year	371,000,000	350,000,000	314,000,000
Amounts Recognized on the Consolidated Balance Sheets
Other assets	7,000,000	39,000,000
Other liabilities	0	0
Net amount recognized	7,000,000	39,000,000
Amounts Recognized in Accumulated OCI, Net of Tax
Net (gain) loss	60,000,000	33,000,000
Prior service credit	0	0
Net amount recognized	60,000,000	33,000,000
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate used in calculating benefit obligations	4.40%	5.00%
Expected return on plan assets used in calculating benefit obligations	5.30%	5.40%
Weighted-Average Assumptions, Net periodic benefit cost:
Weighted-average discount rate used in calculating net periodic benefit cost	5.00%	5.70%
Expected return on plan assets used in calculating net periodic benefit cost	5.30%	5.40%
Assumptions, next year [Abstract]
Discount rate, assumed for next year	4.40%
Expected return on plan assets, assumed for next year	5.30%
Components of net defined benefit pension plan and postretirement benefit plan expense [Abstract]
Service cost	0	0
Interest cost	(15,000,000)	(15,000,000)	16,000,000
Expected return on plan assets	(17,000,000)	(16,000,000)	(16,000,000)
Recognized net actuarial loss (gain)	1,000,000	0	1,000,000
Net periodic benefit expense (recovery)	(1,000,000)	(1,000,000)	1,000,000
Non-U.S. Pension Benefits [Member] | Available-for-sale fixed maturity securities [Member]
Pension plan target allocations by asset category [Abstract]
Debt securities	39.00%	56.00%
Non-U.S. Pension Benefits [Member] | Corporate bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	35,000,000	34,000,000
Non-U.S. Pension Benefits [Member] | U.S. government bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	4,000,000	13,000,000
Non-U.S. Pension Benefits [Member] | Foreign government bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	179,000,000	206,000,000
Non-U.S. Pension Benefits [Member] | CMBS [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Non-U.S. Pension Benefits [Member] | Equity securities [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	59.00%	43.00%
Non-U.S. Pension Benefits [Member] | Common stock [Member]
Change in Plan Assets
Fair value as of end-of-year	96,000,000	57,000,000
Non-U.S. Pension Benefits [Member] | Common Stock Domestic Large Cap Equity [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	0.00%	0.00%
Non-U.S. Pension Benefits [Member] | Common Stock International Equity [Member]
Pension plan target allocations by asset category [Abstract]
Equity securities	0.00%	0.00%
Non-U.S. Pension Benefits [Member] | Invested cash [Member]
Change in Plan Assets
Fair value as of end-of-year	53,000,000	39,000,000
Non-U.S. Pension Benefits [Member] | RMBS [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Non-U.S. Pension Benefits [Member] | CDOs [Member]
Change in Plan Assets
Fair value as of end-of-year	4,000,000	1,000,000
Non-U.S. Pension Benefits [Member] | Qualified Plans [Member]
Estimated future benefit payments [Abstract]
2013	14,000,000
2014	14,000,000
2015	15,000,000
2016	16,000,000
2017	17,000,000
Following five years thereafter	94,000,000
Other Postretirement Benefits [Member]
Change in Plan Assets
Fair value as of beginning-of-year	39,000,000	37,000,000
Actual return on plan assets	3,000,000	3,000,000
Company and participant contributions	15,000,000	15,000,000
Benefits paid	(17,000,000)	(17,000,000)
Medicare Part D subsidy	(2,000,000)	(1,000,000)
Foreign exchange translation	0	0
Fair value as of end-of-year	42,000,000	39,000,000	37,000,000
Amounts Recognized on the Consolidated Balance Sheets
Other assets	0	0
Other liabilities	(97,000,000)	(122,000,000)
Net amount recognized	(97,000,000)	(122,000,000)
Amounts Recognized in Accumulated OCI, Net of Tax
Net (gain) loss	(11,000,000)	5,000,000
Prior service credit	(3,000,000)	(3,000,000)
Net amount recognized	(14,000,000)	2,000,000
Rate of Increase in Compensation
Retiree Life Insurance Plan	4.00%	4.00%
Weighted-Average Assumptions, Benefit obligations:
Weighted-average discount rate used in calculating benefit obligations	4.03%	4.25%
Expected return on plan assets used in calculating benefit obligations	6.50%	6.50%
Weighted-Average Assumptions, Net periodic benefit cost:
Weighted-average discount rate used in calculating net periodic benefit cost	4.25%	5.00%
Expected return on plan assets used in calculating net periodic benefit cost	6.50%	6.50%
Health care cost trend rate [Abstract]
Pre-65 health care cost trend rate	8.00%	8.50%	9.50%
Post-65 health care cost trend rate	8.00%	8.50%	9.50%
Ultimate trend rate	4.50%	4.50%	5.00%
Year that the rate reaches the ultimate trend rate	2020	2021	2020
Effect of one-percentage point change in assumed health care cost trend rates [Abstract]
Effect of one-percentage point increase in assumed health care cost trend rates on accumulated postretirement benefit obligation	4,000,000
Effect of one-percentage point increase in assumed health care cost trend rates on total service and interest cost components	1,000,000
Effect of one-percentage point decrease in assumed health care cost trend rates on accumulated postretirement benefit obligation	(7,000,000)
Effect of one-percentage point decrease in assumed health care cost trend rates on total service and interest cost components	(1,000,000)
Components of net defined benefit pension plan and postretirement benefit plan expense [Abstract]
Service cost	(4,000,000)	(4,000,000)	3,000,000
Interest cost	(7,000,000)	(7,000,000)	9,000,000
Expected return on plan assets	(3,000,000)	(2,000,000)	(2,000,000)
Amortization of prior service cost	(1,000,000)	(1,000,000)	(1,000,000)
Recognized net actuarial loss (gain)	1,000,000	1,000,000	1,000,000
Net periodic benefit expense (recovery)	8,000,000	9,000,000	10,000,000
Estimated amount of amortization from accumulated OCI into net periodic benefit expense [Abstract]
Estimated amount of amortization from accumulated OCI into net periodic benefit expense, next year	1,000,000
Estimated future benefit payments [Abstract]
2013	9,000,000
2014	9,000,000
2015	9,000,000
2016	10,000,000
2017	10,000,000
Following five years thereafter	49,000,000
Other Postretirement Benefits [Member] | Corporate bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Other Postretirement Benefits [Member] | U.S. government bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Other Postretirement Benefits [Member] | Foreign government bonds [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Other Postretirement Benefits [Member] | CMBS [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Other Postretirement Benefits [Member] | Common stock [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Other Postretirement Benefits [Member] | Invested cash [Member]
Change in Plan Assets
Fair value as of end-of-year	42,000,000	39,000,000
Other Postretirement Benefits [Member] | RMBS [Member]
Change in Plan Assets
Fair value as of end-of-year	0	0
Other Postretirement Benefits [Member] | CDOs [Member]
Change in Plan Assets
Fair value as of end-of-year	$ 0	$ 0