Property Plant and Equipment - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Property, Plant, and Equipment Disclosure [Line Items]
Depreciation expense	$ 47,876	$ 48,532	$ 43,517
Interest capitalized	$ 619	$ 797	$ 1,292