Net Assets in Liquidation - Additional Information (Detail)		3 Months Ended		6 Months Ended
	Mar. 31, 2011 USD ($) Unit	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)
Net Assets in Liquidation [Line Items]
Distributable Assets		$ 457,900,000		$ 457,900,000
Cash and cash equivalents and marketable securities		505,800,000		505,800,000
Distributable Cash set aside for projected Trust fees, costs and expenses		24,800,000		24,800,000
Distributable cash pending distribution or set aside and not available for distribution		26,600,000		26,600,000
Accrued investment income		22,700,000		22,700,000	$ 16,700,000
Increase in accrued investment income		10,400,000		6,000,000
Accrued reimbursements of legal fees			$ 1,500,000
Number of Trust Units issued per thousand dollars of allowed general unsecured claims | Unit	1
Amount required to issue one Trust Unit per contingent rights	$ 1,000
Contingent settlement payment				15,000,000
Liquidation Basis of Accounting [Member]
Net Assets in Liquidation [Line Items]
Liquidating distributions payable		1,813,000		1,813,000	1,825,000
Accrued investment income		$ 23,404,000		$ 23,404,000	$ 17,495,000