FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($)		1 Months Ended	12 Months Ended
	Sep. 14, 2018	Sep. 30, 2018	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent liability				$ 5,464,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent liability				5,464,000
Efflux Systems, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent liability				523,000
Efflux Systems, Inc. | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent liability				523,000
Simena LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent liability				4,900,000
Simena LLC | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent liability				4,900,000
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability adjustment included in earnings			$ 102,000	152,000
Change in fair value of contingent consideration			(1,495,000)
Fair value, measurements, recurring | Contingent consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability adjustment included in earnings				$ 152,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Handheld Network Test Tools Business
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration related to the divestiture	$ 2,300,000		800,000
Contingent consideration measurement period	2 years	2 years
Change in fair value of contingent consideration			1,600,000
Change in fair value of contingent consideration			$ 119,000
Maximum | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Handheld Network Test Tools Business
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration related to the divestiture	$ 4,000,000.0	$ 4,000,000.0