Reserves for Expected Costs of Liquidation and Residual Wind-Down Claims (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Summary of residual wind-down claims reserve
Beginning balance	$ 31,115	$ 32,247
Cash paid for Residual Wind-Down Claims	(142)	(1,145)
Ending balance	$ 30,973	$ 30,973