Net Assets in Liquidation - Additional Information (Detail) - USD ($)			3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 01, 2019	Mar. 31, 2011	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2018	Mar. 31, 2019
Net Assets in Liquidation [Line Items]
Distributable Assets			$ 326,100,000		$ 326,100,000
Cash and cash equivalents and marketable securities			452,500,000		452,500,000
Liquidating distributions payable			343,874,000		343,874,000			$ 1,785,000
Distributable Cash set aside for projected Trust fees, costs and expenses			75,700,000		75,700,000
Distributable cash pending distribution or set aside and not available for distribution			93,500,000		93,500,000
Accrued investment income			17,583,000		17,583,000			31,552,000
Change in Future Investment Income			4,800,000		(14,000,000)
Amount required to issue one Trust Unit per contingent rights		$ 1,000
Reversal of contingent settlement obligation				$ (15,000,000)		$ (15,000,000)
Settlement payment obligation							$ 15,000,000
Distributions for new allowed general unsecured claims	$ 68,500,000
Avoidance Action Trust Proposed Agreement [Member]
Net Assets in Liquidation [Line Items]
Term Loan Avoidance Action Claims Allowed	$ 231,000,000
GUC Trust Units [Member]
Net Assets in Liquidation [Line Items]
Liquidating distributions payable			343,900,000		343,900,000
Liquidating distributions payable to Guc			326,100,000		326,100,000
Accrued investment income			$ 16,300,000		$ 16,300,000			$ 30,300,000