FAIR VALUE MEASUREMENTS - Reconciliation of Changes in Level 3 Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Contingent Consideration
Contingent consideration pursuant to divestiture of HNT tools business	$ 2,257	$ 0
Fair value, measurements, recurring
Contingent Purchase Consideration
Balance at March 31, 2018	(5,464)
Change in fair value of contingent consideration	(76)
Payments of contingent consideration	523
Balance at September 30, 2018	(5,017)
Contingent Consideration
Balance at March 31, 2018	0
Contingent consideration pursuant to divestiture of HNT tools business	2,257
Change in fair value of contingent consideration	10
Payments of contingent consideration	0
Balance at September 30, 2018	$ 2,267

Fair Value Of Contingent Consideration Received As Partial Consideration For Divestiture Of Business

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized on the income statement for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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