Postretirement Benefit Plans (Details 9)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
UNITED STATES [Member]
Weighted-average assumptions used to determine benefit obligations/net periodic benefit costs
Discount rate	5.06%	5.40%	6.00%
Expected long-term return on plan assets	7.75%	7.75%	8.00%
UNITED KINGDOM [Member]
Weighted-average assumptions used to determine benefit obligations/net periodic benefit costs
Discount rate	4.90%	5.60%	5.70%
Expected long-term return on plan assets	5.46%	6.78%	6.50%