Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 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	110,600,000			$ 110,600,000
Capital loss carryovers begin to expire				Mar. 31, 2017
Net operating loss carryovers begin to expire				Mar. 31, 2032
Deferred tax asset	116,045,000			$ 116,045,000
Deferred tax assets, valuation allowance	$ 126,959,000			126,959,000
Change in valuation allowance against net deferred tax assets		$ 5,700,000		$ 5,500,000
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Statutory notification period				60 days