Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims - Summary of Activity in Reserves for Residual Wind-Down Claims (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Restructuring And Related Activities [Abstract]
Balance, beginning of year	$ 30,855	$ 32,247
Plus reserves received during the year from MLC			33,807
Less claims allowed during the year	(2,157)	(1,392)	(1,560)
Balance, end of year	$ 28,698	$ 30,855	$ 32,247