Segment Information (Assets by Reportable Segment) (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Segment Reporting Information [Line Items]    
Assets $ 985,062 $ 835,117
Reportable Segment [Member]    
Segment Reporting Information [Line Items]    
Assets 985,062  
Reportable Segment [Member] | Printed Circuit Materials [Member]    
Segment Reporting Information [Line Items]    
Assets 332,712  
Reportable Segment [Member] | High Performance Foams [Member]    
Segment Reporting Information [Line Items]    
Assets 280,585  
Reportable Segment [Member] | Power Electronics Solutions [Member]    
Segment Reporting Information [Line Items]    
Assets 330,631  
Reportable Segment [Member] | Other [Member]    
Segment Reporting Information [Line Items]    
Assets $ 41,134