Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Net (reduction in) additions to reserves for Expected Costs of Liquidation	$ (6,531)	$ 4,678	$ (8,209)	$ 5,398
Reserve for Expected Reporting Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net (reduction in) additions to reserves for Expected Costs of Liquidation	(2,327)	413	(4,146)	4,374
Reserve for Expected Wind-Down Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net (reduction in) additions to reserves for Expected Costs of Liquidation	$ (4,204)	$ 4,265	$ (4,063)	$ 1,024