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, 2015	Mar. 31, 2014	Mar. 31, 2013
Restructuring Cost and Reserve [Line Items]
Expected liquidation date	Feb. 28, 2017
Reserve for Expected Wind-Down Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net increase (decrease in) additions to reserves for Expected Costs of Liquidation	$ 9,000	$ (3,800)	$ 5,200
Reserve for Expected Reporting Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net increase (decrease in) additions to reserves for Expected Costs of Liquidation	$ 400	$ (4,100)	$ 12,300