Retirement Benefit Plans - Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. Plans:
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Assumptions used calculating benefit obligation, discount rate	3.75%	4.41%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Assumptions used calculating net periodic benefit cost, discount rate	4.41%	3.67%	4.42%
Assumptions used calculating net periodic benefit cost, expected long-term return on assets	6.75%	6.75%	6.75%
Non-U.S. Plans:
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Assumptions used calculating benefit obligation, discount rate	2.84%	3.90%
Assumptions used calculating benefit obligation, rate of compensation increase	2.84%	2.77%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Assumptions used calculating net periodic benefit cost, discount rate	3.90%	3.86%	5.13%
Assumptions used calculating net periodic benefit cost, rate of compensation increase	2.77%	2.72%	2.78%
Assumptions used calculating net periodic benefit cost, expected long-term return on assets	6.24%	6.42%	6.49%
U.S. other postretirement benefit plans [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Assumptions used calculating benefit obligation, discount rate	3.50%	4.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Assumptions used calculating net periodic benefit cost, discount rate	4.00%	3.25%	4.25%