Income Taxes - Summary of Deferred Taxes (Detail) $ in Thousands	Sep. 30, 2018 USD ($)
Deferred tax assets:
Reserves for expected costs of liquidation and Residual Wind-Down Claims and Costs	$ 15,564
Net operating and capital loss carryovers	52,301
Gross deferred tax assets	67,865
Less: Valuation allowance	(59,456)
Deferred tax asset, net of valuation allowance	8,409
Deferred tax liabilities:
Accrued investment income	(8,409)
Gross deferred tax liabilities	(8,409)
Net deferred taxes	$ 0