Segment and Enterprise Wide Disclosures - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended					3 Months Ended		6 Months Ended
	Sep. 30, 2013 Segment	Sep. 30, 2013 UNITED STATES	Mar. 31, 2013 UNITED STATES	Sep. 30, 2013 Europe	Mar. 31, 2013 Europe	Sep. 30, 2013 International	Sep. 30, 2012 International	Sep. 30, 2013 International	Sep. 30, 2012 International
Segment Reporting Information [Line Items]
Number of business segments	1
Percentage of total consolidated assets		71.00%	71.00%
Goodwill and intangibles				$ 37.3	$ 35.4
Percentage of total consolidated assets, excluding goodwill and intangibles				9.00%	8.00%
Percentage of total product revenue						7.00%	6.00%	8.00%	6.00%