Property, Plant and Equipment (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	$ 2,001,019,000	$ 1,897,685,000
Accumulated depreciation	1,469,052,000	1,383,141,000
Property, plant and equipment, net	531,967,000	514,544,000
Depreciation expense	89,700,000	88,300,000	86,400,000
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	55,624,000	47,102,000
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	411,149,000	396,611,000
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	1,465,255,000	1,377,814,000
Projects in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment costs	$ 68,991,000	$ 76,158,000