Analysis of Changes in Liability for Product Warranties (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Warranty Liability [Line Items]
Balance at beginning of period	$ 42,067	$ 36,006	$ 31,739
Current year provisions	19,724	26,841	20,565
Costs incurred	(20,945)	(20,185)	(17,499)
Foreign exchange and other	1,745	(595)	1,201
Balance at end of period	$ 42,591	$ 42,067	$ 36,006