Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Tax Credit Carryforward [Line Items]
Current tax benefit or provision	$ 0	$ 0	$ 0	$ 0
Income taxes paid	0	0	0	0
Deferred tax benefit or provision	0	$ 0	0	$ 0
Net operating loss carryovers	144,900,000		$ 144,900,000
Remaining capital loss carryovers expire			Mar. 31, 2020
Net operating loss carryovers begin to expire			Mar. 31, 2032
Deferred tax asset	53,631,000		$ 53,631,000
Deferred tax assets, valuation allowance	55,541,000		55,541,000
Change in valuation allowance against net deferred tax assets	$ (1,400,000)		$ (3,200,000)
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Statutory notification period			60 days