Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims - Summary of Activity in Reserves for Residual Wind-Down Claims (Detail) - Liquidation Basis of Accounting [Member] - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Restructuring Cost and Reserve [Line Items]
Balance, beginning of year	$ 25,406	$ 28,698	$ 30,855
Less claims allowed during the year	(6,661)	(3,292)	(2,157)
Balance, end of year	$ 18,745	$ 25,406	$ 28,698