State Net Operating Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards, amount		$ 4.7
States
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards, amount		$ 10.5
States | Fiscal Year 2014
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward, origination year	2014
Net operating loss carry forwards, amount	$ 2.4
Net operating loss carryforwards, expiration year	2034
States | Fiscal Year 2017
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward, origination year	2017
Net operating loss carry forwards, amount	$ 0.9
Net operating loss carryforwards, expiration year	2036
States | Fiscal Year 2018
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward, origination year	2018
Net operating loss carry forwards, amount	$ 4.0
Net operating loss carryforwards, expiration year	2037
States | Fiscal Year 2019
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward, origination year	2019
Net operating loss carry forwards, amount	$ 3.2
Net operating loss carryforwards, expiration year	2038