XML 121 R104.htm IDEA: XBRL DOCUMENT v3.19.1
Provisions - Employee obligations - North America - Provisions- (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
USD ($)
age
plan
Dec. 31, 2017
USD ($)
age
Post Retirement Plans    
Estimated Future Benefit Payments [Abstract]    
Percentage of reasonably possible increase in actuarial assumption 1.00% 1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption $ 1,535 $ 1,862
Percentage of reasonably possible decrease in actuarial assumption 1.00% 1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption $ (1,194) $ (1,442)
North America    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation 64,832 71,820
Fair value of plan assets (46,114) (52,152)
Provision for pensions 18,718 19,668
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discretionary contributions to the defined benefit pension and postretirement plans 1,037  
North America | Pension Plans    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation 57,455 62,983
North America | Post Retirement Plans    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation 7,377 8,837
USA | Pension Plans    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation 35,062 38,195
Fair value of plan assets (29,038) (32,869)
Provision for pensions $ 6,024 $ 5,326
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discount rate 4.00% 3.50%
Retirement age | age 65 65
CANADA | Pension Plans    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation $ 22,393 $ 24,788
Fair value of plan assets (17,076) (19,283)
Provision for pensions $ 5,317 $ 5,505
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discount rate 3.80% 3.60%
Retirement age | age 62 62
CANADA | Post Retirement Plans    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation $ 7,377 $ 8,837
Provision for pensions $ 7,377 $ 8,837
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discount rate 3.90% 3.65%
Retirement age | age 62 62
Minimum | CANADA | Pension Plans    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Salary increase 2.75% 2.75%
Maximum | CANADA | Pension Plans    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Salary increase 3.00% 3.00%
Not later than one year | Actuarial assumption of medical cost trend rates [member]    
Estimated Future Benefit Payments [Abstract]    
Health care cost trend rate 5.30%  
Not later than one year | North America | Pension Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments $ 3,175  
Not later than one year | North America | Post Retirement Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 197  
Later than one year and not later than two years | North America | Pension Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 3,205  
Later than one year and not later than two years | North America | Post Retirement Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 197  
Later than two years and not later than three years | North America | Pension Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 3,241  
Later than two years and not later than three years | North America | Post Retirement Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 203  
Later than three years and not later than four years | North America | Pension Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 3,247  
Later than three years and not later than four years | North America | Post Retirement Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 203  
Later than four years and not later than five years | North America | Pension Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 3,311  
Later than four years and not later than five years | North America | Post Retirement Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 222  
Later than five years and not later than ten years [member] | North America | Pension Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments 17,178  
Later than five years and not later than ten years [member] | North America | Post Retirement Plans    
Estimated Future Benefit Payments [Abstract]    
Estimated future benefit payments $ 1,393  
Later Than Sixteen Years And Not Later Than Seventeen Years [Member] | Actuarial assumption of medical cost trend rates [member]    
Estimated Future Benefit Payments [Abstract]    
Health care cost trend rate 4.00%  
Globe Metallurgical Inc [Member] | North America | Non Contributory Plans [Member]    
Disclosure of defined benefit plans [line items]    
Number of defined benefit plans sponsored | plan 3