Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	$ 2,267,273	$ 2,142,416
Accumulated depreciation	1,657,877	1,560,844
Property, plant and equipment, net	609,396	581,572
Depreciation expense	103,900	97,300	$ 89,700
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	63,907	55,624
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	458,379	434,403
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	1,645,617	1,576,074
Projects in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	$ 99,370	$ 76,315