Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended			9 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
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
Federal income tax rate	37.00%			39.60%	37.00%
Capital losses carryovers		1,700,000			$ 1,700,000
Net operating loss carryovers		139,100,000			$ 139,100,000
Remaining capital loss carryovers expire					Mar. 31, 2020
Net operating loss carryovers begin to expire					Mar. 31, 2032
Deferred tax asset		52,086,000			$ 52,086,000
Deferred tax assets, valuation allowance		54,393,000			54,393,000
Change in valuation allowance against net deferred tax assets		$ (5,100,000)			$ (5,800,000)
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