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) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	$ 177
Balance, end of period	178
Liquidation Basis of Accounting [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	177	$ 169
Plus addition to reserves	1
Balance, end of period	$ 178	$ 169