Employee Benefits Weighted-average assumptions used to determine future benefit obligations (Details)	Dec. 31, 2013	Dec. 31, 2012
U.K. [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.55%	4.45%
Rate of compensation increase		3.85%
Underlying price inflation	2.40%	2.25%
U.K. [Member] | Minimum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Rate of compensation increase	3.70%
U.K. [Member] | Maximum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Rate of compensation increase	4.40%
U.S. [Member] | Minimum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.97%	3.73%
U.S. [Member] | Maximum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.87%	4.05%
Other [Member] | Minimum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.60%	3.25%
Rate of compensation increase	2.25%	2.25%
Underlying price inflation	1.50%	2.00%
Other [Member] | Maximum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.71%	3.89%
Rate of compensation increase	3.50%	3.50%
Underlying price inflation	2.50%	2.50%