Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims - Summary of Activity in Reserves for Expected Costs of Liquidation (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended																												3 Months Ended				3 Months Ended					3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Trust Professionals [Member]	Jun. 30, 2013 Trust Professionals [Member]	Jun. 30, 2014 Trust Governance [Member]	Jun. 30, 2013 Trust Governance [Member]	Jun. 30, 2014 Other Administrative Expenses [Member]	Jun. 30, 2013 Other Administrative Expenses [Member]	Jun. 30, 2014 Reserve for Expected Wind-Down Costs [Member]	Jun. 30, 2013 Reserve for Expected Wind-Down Costs [Member]	Jun. 30, 2014 Reserve for Expected Wind-Down Costs [Member] Trust Professionals [Member]	Jun. 30, 2013 Reserve for Expected Wind-Down Costs [Member] Trust Professionals [Member]	Jun. 30, 2014 Reserve for Expected Wind-Down Costs [Member] Trust Governance [Member]	Jun. 30, 2013 Reserve for Expected Wind-Down Costs [Member] Trust Governance [Member]	Jun. 30, 2014 Reserve for Expected Wind-Down Costs [Member] Other Administrative Expenses [Member]	Jun. 30, 2013 Reserve for Expected Wind-Down Costs [Member] Other Administrative Expenses [Member]	Jun. 30, 2014 Reserve for Expected Reporting Costs [Member]	Jun. 30, 2013 Reserve for Expected Reporting Costs [Member]	Jun. 30, 2014 Reserve for Expected Reporting Costs [Member] Trust Professionals [Member]	Jun. 30, 2013 Reserve for Expected Reporting Costs [Member] Trust Professionals [Member]	Jun. 30, 2014 Reserve for Expected Reporting Costs [Member] Trust Governance [Member]	Jun. 30, 2013 Reserve for Expected Reporting Costs [Member] Trust Governance [Member]	Jun. 30, 2014 Reserve for Expected Reporting Costs [Member] Other Administrative Expenses [Member]	Jun. 30, 2013 Reserve for Expected Reporting Costs [Member] Other Administrative Expenses [Member]	Jun. 30, 2014 Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member]	Mar. 31, 2014 Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member]	Jun. 30, 2013 Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member]	Mar. 31, 2013 Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member]	Jun. 30, 2014 Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member] Trust Governance [Member]	Jun. 30, 2013 Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member] Trust Governance [Member]	Jun. 30, 2013 Reserve for Avoidance Action Defense Costs [Member]	Mar. 31, 2013 Reserve for Avoidance Action Defense Costs [Member]	Jun. 30, 2013 Reserve for Avoidance Action Defense Costs [Member] Trust Professionals [Member]	Jun. 30, 2014 Reserve for Residual Wind-Down Costs [Member]	Mar. 31, 2014 Reserve for Residual Wind-Down Costs [Member]	Jun. 30, 2013 Reserve for Residual Wind-Down Costs [Member]	Mar. 31, 2013 Reserve for Residual Wind-Down Costs [Member]	Jun. 30, 2014 Reserve for Residual Wind-Down Costs [Member] Trust Professionals [Member]	Jun. 30, 2013 Reserve for Residual Wind-Down Costs [Member] Trust Professionals [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 36,486	$ 61,513							$ 22,529	$ 38,043							$ 12,235	$ 20,442							$ 446	$ 464	$ 491	$ 499			$ 760	$ 898		$ 1,238	$ 1,258	$ 1,394	$ 1,631
Plus additions to (reductions in) reserves	1,844	(1,678)							2,437	141							(593)	(1,819)
Less liquidation costs incurred:
Liquidation costs incurred			(2,131)	(4,664)	(1,388)	(1,430)	(131)	(140)			(1,526)	(3,604)	(917)	(973)	(10)	(13)			(585)	(685)	(453)	(449)	(121)	(127)					(18)	(8)			(138)					(20)	(237)
Ending Balance	$ 34,680	$ 53,601							$ 22,513	$ 33,594							$ 10,483	$ 17,362							$ 446	$ 464	$ 491	$ 499			$ 760	$ 898		$ 1,238	$ 1,258	$ 1,394	$ 1,631