Net Assets in Liquidation - Additional Information (Detail)			3 Months Ended		6 Months Ended	9 Months Ended
	Dec. 15, 2011 USD ($)	Mar. 31, 2011 USD ($) Unit	Dec. 31, 2018 USD ($) Unit	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Unit	Dec. 31, 2018 USD ($) Unit	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			504,600,000			504,600,000
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			34,100,000			34,100,000	$ 16,700,000
Increase in accrued investment income			$ 11,400,000			$ 17,400,000
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
Outstanding or issuable GUC Trust Units | Unit			31,855,504		31,855,504	31,855,504
Avoidance Action Trust [Member]
Net Assets in Liquidation [Line Items]
Cash Transferred to trust	$ 500,000
Amount receivable upon dissolution of the trust						$ 400,000
Liquidation Basis of Accounting [Member]
Net Assets in Liquidation [Line Items]
Liquidating distributions payable			$ 1,792,000			1,792,000	1,825,000
Accrued investment income			$ 34,879,000			34,879,000	17,495,000
Contingent settlement payment							$ 15,000,000
Reversal of contingent settlement obligation					$ 15,000,000	$ 15,000,000