Quantum Corporation Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE - Schedule of Carrying Value and Fair Value of Financial Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017
Carrying Value
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	$ 60,219	$ 65,028
Level 2 fair value measurements \| Fair Value
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	63,302	68,516
Convertible subordinated debt \| Carrying Value
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	62,926	62,827
Convertible subordinated debt \| Level 2 fair value measurements \| Fair Value
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	61,513	60,667
Credit agreement \| Carrying Value \| Revolving credit agreement \| Revolving credit agreement
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	11,888	16,852
Credit agreement \| Level 2 fair value measurements \| Fair Value \| Revolving credit agreement \| Revolving credit agreement
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	13,372	18,490
Term loan agreement \| Carrying Value
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	48,331	48,176
Term loan agreement \| Level 2 fair value measurements \| Fair Value
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total long-term debt	$ 49,930	$ 50,026