Retirement Plans and Profit Sharing Arrangements (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended
	Dec. 31, 2012 Pension Plans	Dec. 31, 2011 Pension Plans	Dec. 31, 2010 Pension Plans	Feb. 28, 2010 Pension Plans Maximum	Dec. 31, 2012 Pension Plans Maximum	Feb. 28, 2010 Pension Plans Minimum	Dec. 31, 2012 Pension Plans Minimum	Dec. 31, 2012 Other Postretirement Benefits	Dec. 31, 2011 Other Postretirement Benefits
Defined Benefit Plan Disclosure
Percentage of Eligible Contribution				10.00%	5.00%	2.50%	2.50%
Yield period of U.S. Treasury Note	5 years
Minimum crediting rate (as a percent)	5.00%
Components of Net Periodic Pension Cost
Service cost	$ 41	$ 38	$ 33
Interest cost	24	23	23					1	1
Expected return on plan assets	(30)	(26)	(23)
Amortization of prior service costs	(1)	(1)	(2)
Amortization of net (gain)/loss	7	1
Other	4	4	3
Net periodic benefit cost	45	39	34
Minimum threshold percentage for amortization of actuarial gains and losses	10.00%
Change in benefit obligation
Benefit obligation at beginning of year	546	469						19	21
Service cost	41	38	33
Interest cost	24	23	23					1	1
Benefits paid	(7)	(6)						(4)	(5)
Participant contributions								3	4
Actuarial gain (loss)	51	40						1	(2)
Settlements	(15)	(18)
Foreign currency rate changes	3
Benefit obligation at end of year	643	546	469					20	19
Change in fair value of plan assets
Fair value of plan assets at the beginning of the year	362	327
Actual return on plan assets	49	(12)
Employer contributions	45	72
Benefits paid	(7)	(6)						(4)	(5)
Settlements	(15)	(18)
Foreign currency rate changes	3	(1)
Fair value of plan assets at the end of the year	437	362	327
Amounts recognized in the Consolidated Balance Sheets
Benefit liability	(214)	(189)
Benefit asset	8	5
Net amount recognized	(206)	(184)
Unrecognized actuarial gain (loss) recognized in accumulated other comprehensive income	101							5
Unrecognized prior service credit (cost) recognized in accumulated other comprehensive income	4							1
Estimated amounts that will be amortized from accumulated other comprehensive income (loss), net of tax, into net periodic benefit cost	1							1
Accumulated benefit obligation for all pension plans	576	493
Plans with accumulated benefit obligations in excess of plan assets:
Accumulated benefit obligation	503	434
Fair value of plan assets	333	282
Plans with projected benefit obligations in excess of plan assets:
Projected benefit obligation	547	470
Fair value of plan assets	$ 333	$ 282
Weighted average assumptions used to determine benefit obligations for pension plans
Discount rates (as a percent)	3.45%	4.15%						3.40%	4.15%
Rates of increase in compensation levels (as a percent)	4.36%	4.27%
Healthcare cost increase rates:
Following year (as a percent)								6.50%	7.00%
Decreasing to the year 2016 (as a percent)								5.00%	5.00%
Weighted average assumptions used to determine net periodic benefit cost for pension plans
Discount rates (as a percent)	4.15%	4.75%	5.28%
Rates of increase in compensation levels (as a percent)	4.27%	4.25%	4.22%
Expected long term rates of return on assets (as a percent)	7.69%	8.00%	8.00%