Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims and Costs - Summary of Activity in Reserves for Residual Wind-Down Claims and Costs (Detail) - Liquidation Basis of Accounting [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	$ 160	$ 17,519	$ 966	$ 19,957
Plus addition to reserves			8
Less claims allowed during the period	0	(2,409)	(814)	(4,846)
Less costs incurred by trust professionals	0	(1)		(2)
Balance, end of period	$ 160	$ 15,109	$ 160	$ 15,109