Income Taxes - Additional Information (Detail) - USD ($)		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Schedule Of Income Taxes [Line Items]
Corporate tax rate			34.00%	34.00%
Net operating loss carry forwards, amount	$ 4,700,000		$ 4,700,000
Income (loss) of foreign subsidiaries before taxes			276,000	$ (220,000)
Deferred tax valuation allowance against assets	448,000		448,000	$ 288,000
Transition tax liability, gross	4,600,000		4,600,000
Decrease in transition tax liability			(1,500,000)
Income tax expense due to tax transition tax liability			3,100,000
Income tax expense resulting from rate change			$ 300,000
Deduction for U.S. federal tax			100.00%
Senario Plan
Schedule Of Income Taxes [Line Items]
Corporate tax rate		21.00%
U.S. federal
Schedule Of Income Taxes [Line Items]
Net operating loss carry forwards, amount	$ 0		$ 0
U.S. federal | Earliest Tax Year
Schedule Of Income Taxes [Line Items]
Open tax years	2014
U.S. federal | Latest Tax Year
Schedule Of Income Taxes [Line Items]
Open tax years	2017
States
Schedule Of Income Taxes [Line Items]
Net operating loss carry forwards, amount	$ 7,000,000		$ 7,000,000
States | Earliest Tax Year
Schedule Of Income Taxes [Line Items]
Open tax years	2011
States | Latest Tax Year
Schedule Of Income Taxes [Line Items]
Open tax years	2017