Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims and Costs - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019
Restructuring Cost and Reserve [Line Items]
Net increase (decrease in) additions to reserves for Expected Costs of Liquidation	$ 1,634,000		$ 855,000	$ 29,138,000	$ 9,434,000
Expected liquidation end date		Oct. 31, 2023		Oct. 31, 2023
Reserves For Residual Wind Down Claims And Costs	169,000			$ 169,000		$ 169,000
Legal Fees Reimbursement [Member]
Restructuring Cost and Reserve [Line Items]
Loss contingency Inestimable loss	10,000,000			10,000,000
Reserve for Expected Wind-Down Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net increase (decrease in) additions to reserves for Expected Costs of Liquidation	1,639,000		(479,000)	22,362,000	3,944,000
Reserves For Residual Wind Down Claims And Costs	200,000			200,000
Reserve for Expected Reporting Costs [Member]
Restructuring Cost and Reserve [Line Items]
Net increase (decrease in) additions to reserves for Expected Costs of Liquidation	$ (5,000)		$ 1,334,000	$ 6,776,000	$ 5,490,000