Revenue and Assets by Geographic Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	$ 609,396	$ 581,572
United States [Member]
Segment Reporting Information [Line Items]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	373,860	331,372
Thailand [Member]
Segment Reporting Information [Line Items]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	182,813	197,981
Various Other Countries besides United States and Thailand [Member]
Segment Reporting Information [Line Items]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	$ 52,723	$ 52,219
Located outside US, in aggregate [Member]
Geographic Areas, Revenues from External Customers [Abstract]
Percentage of net sales to unaffiliated customers	84.00%	84.00%	84.00%
Europe [Member]
Geographic Areas, Revenues from External Customers [Abstract]
Percentage of net sales to unaffiliated customers	22.00%	21.00%	21.00%
Asia [Member]
Geographic Areas, Revenues from External Customers [Abstract]
Percentage of net sales to unaffiliated customers	59.00%	59.00%	60.00%
China, including Hong-Kong [Member]
Geographic Areas, Revenues from External Customers [Abstract]
Percentage of net sales to unaffiliated customers	30.00%	28.00%	29.00%
Taiwan [Member]
Geographic Areas, Revenues from External Customers [Abstract]
Percentage of net sales to unaffiliated customers	12.00%	14.00%	13.00%