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Income Taxes - Additional Information (Detail) - USD ($) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2017 | Mar. 31, 2019 | Mar. 31, 2018
Income Taxes [Line Items] |  |  |
Valuation allowance |  | $ 4,917,000 | $ 1,074,000
Deferred Tax Assets, gross |  | 3,898,000 |
Liability unrecognized tax benefits |  | $ 0 | 0
Percentage of corporate income tax rate | 35.00% | 21.00% |
Income tax benefit from remeasurement of deferred tax assets and liabilities |  |  | 971,000
One-time transition tax on accumulated foreign earnings |  |  | 185,000
Tax related to global intangible low-taxed income |  | $ 11,000 |
Foreign derived intangible income (FDII) effective tax rate | 13.125% |  |
Incremental U.S. tax savings on foreign derived intangible income |  | 69,000 |
International Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Net operating loss |  | $ 200,000 |
Earliest Tax Year [Member] | International Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Net operating loss, expiration date |  | Mar. 31, 2021 |
Open tax year |  | 2015 |
Earliest Tax Year [Member] | State Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Open tax year |  | 2014 |
Earliest Tax Year [Member] | Federal Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Open tax year |  | 2015 |
Latest Tax Year [Member] | International Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Net operating loss, expiration date |  | Mar. 31, 2023 |
Open tax year |  | 2018 |
Latest Tax Year [Member] | State Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Open tax year |  | 2018 |
Latest Tax Year [Member] | Federal Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Open tax year |  | 2018 |
Energy Steel [Member] | State Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Net operating loss |  | $ 4,279,000 |
Other Assets [Member] |  |  |
Income Taxes [Line Items] |  |  |
Deferred income tax asset foreign |  | 37,000 | $ 15,000
Assets Held for Sale [Member] | State Tax Jurisdictions [Member] |  |  |
Income Taxes [Line Items] |  |  |
Deferred Tax Assets, gross |  | 126,000 |
Net operating loss carryforwards, valuation allowance |  | 34,000 |
Investment Tax Credit Carryforward [Member] |  |  |
Income Taxes [Line Items] |  |  |
Deferred income taxes include the impact of state investment tax credits |  | 275,000 |
State investment tax credits with an unlimited carryforward period |  | $ 794,000 |
Investment Tax Credit Carryforward [Member] | Maximum [Member] |  |  |
Income Taxes [Line Items] |  |  |
Expiration date of state investment tax credits |  | Mar. 31, 2033 |
Investment Tax Credit Carryforward [Member] | Minimum [Member] |  |  |
Income Taxes [Line Items] |  |  |
Expiration date of state investment tax credits |  | Mar. 31, 2020 |

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- Definition Amount of the difference between reported income tax expense (benefit) and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for foreign-derived intangible income. + References No definition available. + Details
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