Pension Plans, Retirement Benefits and Savings Plans (details) - Summary of Funded Status and Obligations (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Plans [Member]
Defined benefit plan disclosure
Accrued under-funded benefit plan liabilities	$ (402,000,000)	$ (389,000,000)
Net actuarial loss (gain)	1,363,000,000	1,275,000,000
Total amount recognized in accumulated other comprehensive income	1,363,000,000	1,275,000,000
Total accumulated benefit obligation	3,210,000,000	2,830,000,000
Aggregate projected benefit obligation for pension plans with an accumulated benefit obligation in excess of plan assets	3,250,000,000
Aggregate accumulated benefit obligation for pension plans with an accumulated benefit obligation in excess of plan assets	3,200,000,000
Fair value of plan assets for pension plans with an accumulated benefit obligation in excess of plan assets	2,850,000,000	2,490,000,000
Service cost	113,000,000	98,000,000	96,000,000
Interest cost on benefit obligation	138,000,000	135,000,000	128,000,000
Expected return on plan assets	(187,000,000)	(182,000,000)	(185,000,000)
Amortization of unrecognized prior service benefit			(3,000,000)
Net periodic benefit cost, amortization of unrecognized net actuarial loss (gain)	89,000,000	76,000,000	60,000,000
Net periodic benefit cost, net benefit expense	153,000,000	127,000,000	96,000,000
Other changes in benefit plan assets and benefit obligations recognized in other comprehensive income, net actuarial loss (gain)	176,000,000	388,000,000	27,000,000
Other changes in benefit plan assets and benefit obligations recognized in other comprehensive income, amortization of prior service benefit			3,000,000
Other changes in benefit plan assets and benefit obligations recognized in other comprehensive income, amortization of net actuarial gain (loss)	(89,000,000)	(76,000,000)	(60,000,000)
Total other changes in benefit plan assets and benefit obligations recognized in other comprehensive income	87,000,000	312,000,000	(30,000,000)
Total other changes recognized in net benefit expense and other comprehensive income	240,000,000	439,000,000	66,000,000
Estimated net actuarial loss that will be amortized from other comprehensive income into net periodic benefit cost over the next fiscal year	107,000,000
Assumptions used to determine net periodic benefit cost, expected long-term rate of return on assets (percent)	7.50%	8.00%
Pension Plans, Retirement Benefits and Savings Plans, Plan Assets investment strategy	The Company's overall investment strategy is to achieve a mix of approximately 85% to 90% of investments for long-term growth and 10% to 15% for near-term benefit payments with a wide diversification of asset types, fund strategies and fund managers. The current target allocations for plan assets are 55% to 65% equity securities and 20% to 40% fixed income securities, with the remainder allocated to short-term securities. Equity securities primarily include investments in large, medium and small-cap companies primarily located in the United States. Fixed income securities include corporate bonds of companies from diversified industries, mortgage-backed securities, U.S. Treasury securities and debt securities issued by foreign governments. Other investments include two private equity funds held by the Company's qualified defined benefit pension plan. One private equity fund is focused on financial companies, and the other is focused on real estate-related investments. Other investments at December 31, 2011 also included a hedge fund which was a multi-strategy "fund of funds."
Benefits expected to be paid, 2013	152,000,000
Benefits expected to be paid, 2014	165,000,000
Benefits expected to be paid, 2015	176,000,000
Benefits expected to be paid, 2016	187,000,000
Benefits expected to be paid, 2017	198,000,000
Benefits expected to be paid, 2018 through 2022	1,118,000,000
Qualified Domestic Pension Plan [Member]
Defined benefit plan disclosure
Accrued under-funded benefit plan liabilities	(294,000,000)	(292,000,000)
Net actuarial loss (gain)	1,300,000,000	1,220,000,000
Total amount recognized in accumulated other comprehensive income	1,300,000,000	1,220,000,000
Total accumulated benefit obligation	3,010,000,000	2,650,000,000
Nonqualified and Foreign Pension Plans [Member]
Defined benefit plan disclosure
Accrued under-funded benefit plan liabilities	(108,000,000)	(97,000,000)
Net actuarial loss (gain)	63,000,000	55,000,000
Total amount recognized in accumulated other comprehensive income	63,000,000	55,000,000
Total accumulated benefit obligation	200,000,000	180,000,000
Postretirement Benefit Plans [Member]
Defined benefit plan disclosure
Accrued under-funded benefit plan liabilities	(204,000,000)	(227,000,000)
Net actuarial loss (gain)	(50,000,000)	(31,000,000)
Service cost			1,000,000
Interest cost on benefit obligation	12,000,000	13,000,000	14,000,000
Expected return on plan assets	(1,000,000)	(1,000,000)	(1,000,000)
Net periodic benefit cost, amortization of unrecognized net actuarial loss (gain)	(1,000,000)
Net periodic benefit cost, net benefit expense	10,000,000	12,000,000	14,000,000
Other changes in benefit plan assets and benefit obligations recognized in other comprehensive income, net actuarial loss (gain)	11,000,000	(5,000,000)	(8,000,000)
Other changes in benefit plan assets and benefit obligations recognized in other comprehensive income, plan amendments	(31,000,000)
Other changes in benefit plan assets and benefit obligations recognized in other comprehensive income, amortization of net actuarial gain (loss)	1,000,000
Total other changes in benefit plan assets and benefit obligations recognized in other comprehensive income	(19,000,000)	(5,000,000)	(8,000,000)
Total other changes recognized in net benefit expense and other comprehensive income	(9,000,000)	7,000,000	6,000,000
Estimated net actuarial loss that will be amortized from other comprehensive income into net periodic benefit cost over the next fiscal year	less than $1 million
Estimated prior service cost to be amortized over the next fiscal year	3,000,000
Assumptions used to determine net periodic benefit cost, expected long-term rate of return on assets (percent)	5.00%	5.00%
Pension Plans, Retirement Benefits and Savings Plans, Plan Assets investment strategy	The Company's overall investment strategy is to achieve a mix of approximately 35% to 65% of investments for long-term growth and 35% to 60% for near-term insurance payments with a wide diversification of asset types, fund strategies and fund managers. The current target allocations for plan assets are 25% to 75% fixed income securities, with the remainder allocated to short-term securities. Fixed income securities include corporate bonds of companies from diversified industries, mortgage-backed securities and U.S. Treasuries.
Benefits expected to be paid, 2013	15,000,000
Benefits expected to be paid, 2014	15,000,000
Benefits expected to be paid, 2015	15,000,000
Benefits expected to be paid, 2016	15,000,000
Benefits expected to be paid, 2017	15,000,000
Benefits expected to be paid, 2018 through 2022	$ 70,000,000