Segment Reporting (Narrative) (Details) (USD $)	12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009
Long-lived assets	2,141,063,000	2,118,576,000
Minimum [Member]
Segment reporting long-lived assets, percent	10.00%	10.00%	10.00%
Minimum [Member] | Other Country [Member]
Segment reporting net sales percent	10.00%	10.00%	10.00%
Singapore [Member]
Net sales	578,200,000	428,000,000	444,200,000
Long-lived assets	17,300,000	13,800,000
China [Member]
Segment reporting net sales percent	38.00%	33.00%	32.00%
Segment reporting long-lived assets, percent	41.00%	42.00%	43.00%
United States [Member]
Segment reporting net sales percent	10.00%	14.00%	16.00%
Malaysia [Member]
Segment reporting net sales percent		11.00%	13.00%
Mexico [Member]
Segment reporting net sales percent	15.00%	15.00%	11.00%
Segment reporting long-lived assets, percent	16.00%	17.00%	15.00%
Other Country [Member]
Number of countries accounting for net sales	0	0	0
Number of countries accounting for long-lived assets	0	0	0