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		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 43,107	$ 61,663	$ 61,513	$ 76,111
Plus additions to (less reductions in) reserves	646	13,563	(7,563)	18,961
Less liquidation costs incurred:
Ending Balance	39,363	69,143	39,363	69,143
Trust Professionals [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(2,824)	(4,365)	(9,915)	(20,846)
Trust Governance [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(1,446)	(1,587)	(4,356)	(4,800)
Other Administrative Expenses [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(120)	(131)	(316)	(283)
Reserve for Expected Wind-Down Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	26,468	43,261	38,043	56,815
Plus additions to (less reductions in) reserves	578	6,776	(3,485)	7,800
Less liquidation costs incurred:
Ending Balance	24,509	45,311	24,509	45,311
Reserve for Expected Wind-Down Costs [Member] | Trust Professionals [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(1,551)	(3,669)	(7,033)	(16,008)
Reserve for Expected Wind-Down Costs [Member] | Trust Governance [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(973)	(1,044)	(2,977)	(3,250)
Reserve for Expected Wind-Down Costs [Member] | Other Administrative Expenses [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(13)	(13)	(39)	(46)
Reserve for Expected Reporting Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	14,272	14,597	20,442	13,320
Plus additions to (less reductions in) reserves	68	6,787	(4,078)	11,161
Less liquidation costs incurred:
Ending Balance	13,108	20,458	13,108	20,458
Reserve for Expected Reporting Costs [Member] | Trust Professionals [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(675)	(326)	(1,628)	(2,382)
Reserve for Expected Reporting Costs [Member] | Trust Governance [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(450)	(482)	(1,351)	(1,414)
Reserve for Expected Reporting Costs [Member] | Other Administrative Expenses [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(107)	(118)	(277)	(227)
Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	494	572	499	647
Plus additions to (less reductions in) reserves
Less liquidation costs incurred:
Ending Balance	471	511	471	511
Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member] | Trust Professionals [Member]
Less liquidation costs incurred:
Liquidation costs incurred
Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member] | Trust Governance [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(23)	(61)	(28)	(136)
Reserve for Indenture Trustee/Fiscal and Paying Agent Costs [Member] | Other Administrative Expenses [Member]
Less liquidation costs incurred:
Liquidation costs incurred
Reserve for Avoidance Action Defense Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	588	1,095	898	1,280
Plus additions to (less reductions in) reserves
Less liquidation costs incurred:
Ending Balance		1,067		1,067
Reserve for Avoidance Action Defense Costs [Member] | Trust Professionals [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(588)	(28)	(898)	(213)
Reserve for Avoidance Action Defense Costs [Member] | Trust Governance [Member]
Less liquidation costs incurred:
Liquidation costs incurred
Reserve for Avoidance Action Defense Costs [Member] | Other Administrative Expenses [Member]
Less liquidation costs incurred:
Liquidation costs incurred
Reserve for Residual Wind-Down Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	1,285	2,138	1,631	4,049
Plus additions to (less reductions in) reserves
Less liquidation costs incurred:
Ending Balance	1,275	1,796	1,275	1,796
Reserve for Residual Wind-Down Costs [Member] | Trust Professionals [Member]
Less liquidation costs incurred:
Liquidation costs incurred	(10)	(342)	(356)	(2,243)
Reserve for Residual Wind-Down Costs [Member] | Trust Governance [Member]
Less liquidation costs incurred:
Liquidation costs incurred
Reserve for Residual Wind-Down Costs [Member] | Other Administrative Expenses [Member]
Less liquidation costs incurred:
Liquidation costs incurred				$ (10)