Annual report pursuant to Section 13 and 15(d)

Supplemental Balance Sheets and Statements of Operations - Property, Plant and Equipment (Details)

v3.19.1
Supplemental Balance Sheets and Statements of Operations - Property, Plant and Equipment (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Mar. 31, 2018
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 1,375,731 $ 1,271,930
Accumulated depreciation (880,451) (866,614)
Property, plant and equipment 495,280 405,316
Land and land improvements    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 62,232 66,150
Buildings    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 199,319 186,207
Machinery and equipment    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 916,737 895,914
Furniture and fixtures    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 82,306 72,811
Construction in progress    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 105,857 46,391
Other Capitalized Property Plant and Equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 9,280 $ 4,457