State Net Operating Loss (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2013
Deferred Tax Assets, Net Operating Losses, Capital Losses, and Tax Credits Carryforwards [Line Items]
Operating Loss Carryforward, Origination Year	2008
U.S. States | Fiscal Year 2008
Deferred Tax Assets, Net Operating Losses, Capital Losses, and Tax Credits Carryforwards [Line Items]
Operating loss carryforwards, amount	$ 1.3
Operating loss carryforwards, expiration year	2018