Summary of Open Tax Years (Detail)	12 Months Ended
	Mar. 31, 2013
Minimum | U.S. federal
Income Tax Examination [Line Items]
Open tax years	2009
Minimum | U.S. States
Income Tax Examination [Line Items]
Open tax years	2008
Minimum | Foreign
Income Tax Examination [Line Items]
Open tax years	2006
Maximum | U.S. federal
Income Tax Examination [Line Items]
Open tax years	2012
Maximum | U.S. States
Income Tax Examination [Line Items]
Open tax years	2012
Maximum | Foreign
Income Tax Examination [Line Items]
Open tax years	2012