XML 104 R116.htm IDEA: XBRL DOCUMENT v2.4.0.8
PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Narrative) (Details) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]      
Current Fiscal Year End Date --12-31    
Minimum participants percentage 15.00%    
Accumulated benefit obligation for defined benefit pension plans $ 1,091,400,000 $ 1,204,700,000  
Maturity period of security 10 years    
Reserve for investment commitments 8,700,000    
Sei Special Situations Fund [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Redemption request notice period, days 95 days    
Structured Finance [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Redemption request notice period, days 90 days    
Real Estate [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Redemption request notice period, days 45 days    
Withdrawal request notice period, days 65 days    
Pension Benefits [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Net Periodic Benefit Cost 52,100,000 55,200,000 37,800,000
Annual costs for defined contribution plan 6,800,000 6,700,000 5,700,000
Participant contributions 0 0  
Other Postretirement Benefit Expense 17,400,000 28,100,000 26,800,000
Pension and Other Postretirement Benefit Expense 76,300,000 90,000,000 70,300,000
Other Benefits [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Net Periodic Benefit Cost 17,400,000 28,100,000 26,800,000
Participant contributions 5,600,000 4,600,000  
Defined Benefit Postretirement Health Coverage [Member] | United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] | Prior To Age65 [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Annual limit on medical coverage for each participant 7,000    
Defined Benefit Postretirement Health Coverage [Member] | United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] | After Age65 [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Annual limit on medical coverage for each participant 3,000    
Defined Benefit Postretirement Health Coverage [Member] | Northshore [Member] | After Age65 [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Annual limit on medical coverage for each participant 2,000    
Minimum [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.36%    
Expected period of long-term return on assets 3 years    
Minimum [Member] | Defined Benefit Postretirement Health Coverage [Member] | Northshore [Member] | Prior To Age65 [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Annual limit on medical coverage for each participant 4,020    
Maximum [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.66%    
Expected period of long-term return on assets 5 years    
Maximum [Member] | Defined Benefit Postretirement Health Coverage [Member] | Northshore [Member] | Prior To Age65 [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Annual limit on medical coverage for each participant 4,500    
United States [Member] | Pension Benefits [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.57% 3.70%  
Projected yield, number of bonds used 494    
United States [Member] | Other Benefits [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.57% 3.70%  
Canada [Member] | Pension Benefits [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.50% 3.75%  
Projected yield, number of bonds used 334    
Canada [Member] | Other Benefits [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.75% 4.00%  
Tilden, Empire, Hibbing and United Taconite [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Term of labor contracts with USW 37 months    
Number of USW employees covered by labor contracts 2,400    
Percentage of total workforce covered by labor contract 32.00%    
Funding of bargaining unit pension plans and VEBAs 65,700,000    
Bloom Lake [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Term of labor contracts with USW 3 years    
Pointe Noire [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Term of labor contracts with USW 6 years    
Increased in Cost of Employment over Life of Union Contract 26.00%    
Pinnacle Complex and Oak Grove [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Number of USW employees covered by labor contracts 800    
Percentage of total workforce covered by labor contract 11.00%    
Contribution rate per hour worked 8.10 8.10 6.50
Annual costs for defined contribution plan 14,900,000 14,900,000 9,500,000
Underfunded Liability Estimate $ 342,000,000