Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
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
Capital losses carryovers	182,400,000		182,400,000
Net operating loss carryovers	118,300,000		$ 118,300,000
Capital loss carryovers begin to expire			Mar. 31, 2017
Net operating loss carryovers begin to expire			Mar. 31, 2032
Deferred tax asset	119,095,000		$ 119,095,000
Deferred tax assets, valuation allowance	133,443,000		133,443,000
Change in valuation allowance against net deferred tax assets	$ 6,500,000		$ 12,000,000
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Statutory notification period			60 days