Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Tax Credit Carryforward [Line Items]
Current tax benefit or provision	$ 0	$ 0
Income taxes paid	0	0
Deferred tax benefit or provision	0	$ 0
Capital losses carryovers	24,300,000
Net operating loss carryovers	$ 131,800,000
Capital loss carryovers begin to expire	Mar. 31, 2018
Net operating loss carryovers begin to expire	Mar. 31, 2032
Deferred tax asset	$ 61,836,000
Deferred tax assets, valuation allowance	67,704,000
Change in valuation allowance against net deferred tax assets	$ 400,000
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Statutory notification period	60 days