Pension and Other Postretirement Benefits - Multiemployer Plans (Details 6) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 employees	Dec. 31, 2012	Dec. 31, 2011
Multiemployer Plans [Line Items]
Contributions to multiemployer plans	$ 22.1	$ 19.6	$ 20.0
Number of Employees	6,400
Steelworkers Pension Trust [Member]
Multiemployer Plans [Line Items]
Contributions to multiemployer plans	7.3	7.0	7.2
IAM National Pension Fund's National Pension Plan [Member]
Multiemployer Plans [Line Items]
Contributions to multiemployer plans	14.8	12.6	12.3
Multiemployer Plan, Individually Insignificant Multiemployer Plans [Member]
Multiemployer Plans [Line Items]
Contributions to multiemployer plans	0	0	0.5
Walbridge Tube [Member] | Steelworkers Pension Trust [Member]
Multiemployer Plans [Line Items]
Number of Employees	90
Ashland Works [Member] | Steelworkers Pension Trust [Member]
Multiemployer Plans [Line Items]
Number of Employees	820
Zanesville Works [Member] | IAM National Pension Fund's National Pension Plan [Member]
Multiemployer Plans [Line Items]
Number of Employees	160
Butler Works [Member] | IAM National Pension Fund's National Pension Plan [Member]
Multiemployer Plans [Line Items]
Number of Employees	1,200
Ashland coke plant [Member] | PACE Industry Union-Management Pension Fund [Member]
Multiemployer Plans [Line Items]
Multiemployer Plans Withdrawal Obligation		$ 1.8
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member] | Mansfield Works [Member] | Steelworkers Pension Trust [Member]
Multiemployer Plans [Line Items]
Number of Employees	280
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member] | Middletown Works [Member] | IAM National Pension Fund's National Pension Plan [Member]
Multiemployer Plans [Line Items]
Number of Employees	1,650