Income Taxes - Additional Information (Detail) - USD ($)		12 Months Ended
	Apr. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2013	Mar. 31, 2012
Tax Credit Carryforward [Line Items]
Current tax benefit or provision		$ 0	$ 0	$ 0
Income taxes paid		0	0	0
Deferred tax benefit or provision		$ 0	0	$ 0
Federal income tax rate		39.60%
Capital losses carryovers		$ 1,700,000	1,700,000		$ 22,600,000	$ 158,100,000
Net operating loss carryovers		$ 139,500,000
Remaining capital loss carryovers expire		Mar. 31, 2020
Net operating loss carryovers begin to expire		Mar. 31, 2032
Deferred tax asset		$ 52,217,000	60,747,000
Deferred tax assets, valuation allowance		60,179,000	67,286,000
Change in valuation allowance against net deferred tax assets		7,100,000	54,200,000
Tax Year 2013 [Member]
Tax Credit Carryforward [Line Items]
Capital losses carryovers		$ 22.6
Tax Year 2012 [Member]
Tax Credit Carryforward [Line Items]
Capital losses carryovers			$ 158.1
Subsequent Event [Member]
Tax Credit Carryforward [Line Items]
Federal income tax rate	37.00%
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Statutory notification period		60 days