Property, Plant, and Equipment, net (Tables)
 3 Months Ended
Mar. 31, 2018
Property, Plant and Equipment [Abstract]  
Components of property, plant and equipment, net
The following table details the major components of property, plant, and equipment, net:
(in millions)
March 31, 2018
 
December 31, 2017
Land
$
7.5

 
$
7.7

Buildings and improvements
105.0

 
103.2

Machinery, equipment, and other
480.0

 
441.1

Subtotal
592.5

 
552.0

Less accumulated depreciation
(389.1
)
 
(369.0
)
Total
$
203.4

 
$
183.0



Depreciation expense totaled $11.9 million and $11.7 million for the three months ended March 31, 2018 and 2017, respectively.