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		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	$ 15,109	$ 22,710	$ 19,957	$ 26,629
Plus additions to reserves	6,484		6,484
Plus reclassification of accrued liability	417		417
Less claims allowed during the period	(5,256)	(1,582)	(10,102)	(5,497)
Balance, end of period	16,753	21,127	16,753	21,127
Trust Professionals [Member]
Restructuring Cost and Reserve [Line Items]
Less costs incurred by trust professionals	$ (1)	$ (1)	$ (3)	$ (5)