Segment and Enterprise Wide Disclosures - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting Information [Line Items]
Number of business segments	1
UNITED STATES
Segment Reporting Information [Line Items]
Percentage of total consolidated assets	71.00%	68.00%
Europe
Segment Reporting Information [Line Items]
Goodwill and intangibles	35.4	37.0
Percentage of total consolidated assets, excluding goodwill and intangibles	8.00%	8.00%
International
Segment Reporting Information [Line Items]
Percentage of total product revenue	7.00%	8.00%	8.00%