Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims and Costs - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Expected liquidation end date			Mar. 31, 2021
Reserve for Expected Wind-Down Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net (additions to) reductions in reserves for Expected Costs of Liquidation	$ (1,500)	$ 1,600	$ (6,200)	$ 22,400
Reserve for Expected Reporting Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net (additions to) reductions in reserves for Expected Costs of Liquidation	$ (200)	$ (5,000)	$ (1,800)	$ 6,800