Leases and Rentals - Additional Information (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Capital Leased Assets [Line Items]      
Depreciation on capital leases (less than $0.1 million in 2012) $ 0.4 $ 0.2 $ 0.1
Rental expense under operating leases 9.9 9.7 9.1
Machinery and equipment      
Capital Leased Assets [Line Items]      
Capital lease obligations incurred $ 1.6    
Minimum | Capital Lease      
Capital Leased Assets [Line Items]      
Capital lease term 24 months    
Maximum | Capital Lease      
Capital Leased Assets [Line Items]      
Capital lease term 60 months