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Fair Value Measurements - Additional Information (Detail) $ in Millions | 6 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2018 | Dec. 31, 2017 Contract | Mar. 31, 2017 USD ($) Contract
Fair Value Disclosures [Abstract] |  |  |
Cash equivalents maturity period, days | 90 days | 90 days |
Number of contracts outstanding | Contract |  | 0 |
Predecessor |  |  |
Fair Value Disclosures [Abstract] |  |  |
Number of contracts outstanding | Contract |  |  | 6
Notional value of foreign exchange contract | $ |  |  | $ 1.5
Predecessor | Forward Contracts |  |  |
Fair Value Disclosures [Abstract] |  |  |
Gain (loss) on Derivatives | $ |  |  | $ (0.7)

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- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
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