Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Taxes [Line Items]
Net operating loss carry forwards expiration period	Fiscal 2015 through fiscal 2034
Stock-based compensation tax deductions in excess of book compensation expense	$ 46,700,000
Deferred tax asset stock-based compensation	10,519,000	10,324,000
Net deferred tax liability	6,415,000	5,554,000
Amortization period of deferred tax liability (years)	15 years
Restatement Adjustment
Income Taxes [Line Items]
Overstatement of the valuation allowance which offset net overstatement of deferred tax asset	11,000,000
Prior year understated amount
Income Taxes [Line Items]
Deferred tax asset stock-based compensation	3,500,000
Prior year understated amount | Scenario, Adjustment
Income Taxes [Line Items]
Stock-based compensation tax deductions in excess of book compensation expense	14,500,000
Federal
Income Taxes [Line Items]
Net operating loss carry forwards	193,000,000
Research and development credit carry forwards	12,500,000
State
Income Taxes [Line Items]
Net operating loss carry forwards	193,000,000
Net operating loss carry forwards expired	1,200,000
Research and development credit carry forwards	$ 5,800,000