Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Restructuring Cost and Reserve [Line Items]
Net (reduction in) additions to reserves for Expected Costs of Liquidation	$ (7,910)	$ 17,488	$ 52,993
Liquidation period extended	Dec. 31, 2016
Reserve for Expected Reporting Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net (reduction in) additions to reserves for Expected Costs of Liquidation	(4,067)	12,293	20,560
Reserve for Expected Wind-Down Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net (reduction in) additions to reserves for Expected Costs of Liquidation	$ (3,843)	$ 5,195	$ 32,434