Retirement Plans and Postretirement Medical Benefits (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 UK Plan [Member]	Dec. 31, 2011 UK Plan [Member]	Dec. 31, 2012 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2011 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2010 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2012 United States Pension Plans of US Entity, Defined Benefit [Member]	Dec. 31, 2012 Foreign Pension Plans, Defined Benefit [Member]	Dec. 31, 2012 US Nonpension Plan [Member] Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2011 US Nonpension Plan [Member] Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 30,000,000	$ 30,000,000
Defined Benefit Plan Historical Health Care Trend Rate	7.50%	7.50%
Defined Benefit Plan, Benefit Obligation					282,857,000	285,828,000	280,386,000			256,000,000	262,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year								10,000,000	20,000,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets			370,000,000	326,000,000
Nominal Rate of Return on Pension Plan								7.25%	7.25%
Subsequent Event, Amount, Lower Range	0
Subsequent Event, Amount, Higher Range	$ 15
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets	7.25%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year	7.00%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%