Pension and Postretirement Benefits - Weighted-average assumptions used to determine benefit obligations (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Pension Plans | Funded Plans
Weighted-average assumptions used to determine benefit obligations
Discount rate	4.89%	4.11%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.09%	4.93%
Expected return on plan assets	3.90%	4.20%
Pension Plans | Unfunded Pension Plans
Weighted-average assumptions used to determine benefit obligations
Discount rate	4.60%	3.80%
Rate of compensation increase	3.00%	4.50%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	3.80%	4.75%
Rate of compensation increase	4.50%	4.50%
US Postretirement Benefit Plans
Weighted-average assumptions used to determine benefit obligations
Discount rate	4.65%	3.85%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	3.85%	4.70%
Expected return on plan assets	0.00%	4.65%
Foreign Pension Plans
Weighted-average assumptions used to determine benefit obligations
Discount rate	4.67%	4.06%
Rate of compensation increase	3.00%	3.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.03%	4.65%
Expected return on plan assets	5.44%	5.45%
Rate of compensation increase	3.00%	3.00%