Union Contracts (Details)	Sep. 30, 2017 employees
Mansfield OH Works [Member]
Concentration Risk [Line Items]
Entity Number of Employees	305
Dearborn Works [Member]
Concentration Risk [Line Items]
Entity Number of Employees	1,165
Rockport IN Works [Member]
Concentration Risk [Line Items]
Entity Number of Employees	320
Walbridge Tube [Member]
Concentration Risk [Line Items]
Entity Number of Employees	100
Middletown Works [Member]
Concentration Risk [Line Items]
Entity Number of Employees	1,720
Ashland Works [Member]
Concentration Risk [Line Items]
Entity Number of Employees	625