Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2013	Mar. 31, 2012
Tax Credit Carryforward [Line Items]
Current tax benefit or provision			$ 0	$ 0	$ 0
Income taxes paid			0
Deferred tax benefit or provision			$ 0	0	0
Federal income tax rate	37.00%	39.60%	37.00%
Capital losses carryovers			$ 1,700,000	1,700,000	1,700,000	$ 22,600,000	$ 158,100,000
Net operating loss carryovers			$ 139,300,000
Remaining capital loss carryovers expire			Mar. 31, 2020
Net operating loss carryovers begin to expire			Mar. 31, 2032
Deferred tax asset			$ 52,150,000	52,217,000
Deferred tax assets, valuation allowance			54,740,000	60,179,000
Change in valuation allowance against net deferred tax assets			$ (5,400,000)	(7,100,000)
Tax Year 2013 [Member]
Tax Credit Carryforward [Line Items]
Capital losses carryovers				$ 22,600,000
Tax Year 2012 [Member]
Tax Credit Carryforward [Line Items]
Capital losses carryovers					$ 158,100,000
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Statutory notification period			60 days