Income Taxes - Summary of Deferred Taxes (Detail) $ in Thousands	Dec. 31, 2020 USD ($)
Deferred tax assets:
Reserves for expected costs of liquidation and Residual Wind-Down Claims and Costs	$ 1,072
Net operating loss carryovers	54,397
Gross deferred tax assets	55,469
Less: Valuation allowance	(55,466)
Deferred tax asset, net of valuation allowance	3
Deferred tax liabilities:
Accrued investment income	(3)
Gross deferred tax liabilities	(3)
Net deferred taxes	$ 0