Income Taxes - Reconciliation of the Financial Statement Recognition and Measurement of Uncertain Tax Positions During the Current Fiscal Year (Detail)	12 Months Ended
	Mar. 31, 2018 USD ($)
Income Tax Disclosure [Abstract]
Balance as of March 31, 2017	$ 1,884,000
Additions based on tax positions related to the current year	236,000
Additions for tax positions of prior years	8,000
Reductions for tax positions related to the current year	0
Reductions for tax positions of prior years	(656,000)
Balance as of March 31, 2018	$ 1,472,000