REVENUE - Impact of Adopting ASC 606 on Unaudited Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Apr. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Assets
Cash and cash equivalents	$ 8,729		$ 9,424	$ 17,307	$ 15,542
Accounts receivable, net	14,804	$ 9,020	8,736
Revenue earned but not billed	3,746
Inventories, net	13,403		7,826
Deferred contract costs	0		1,000
Prepaid expenses and other current assets	695		2,467
Total current assets	41,377		29,453
Property and equipment, net	12,010		12,894
Other intangible assets, net	2,469		2,868
Other long-term assets	165		110
Total assets	56,021		45,325
Liabilities and Shareholders’ Equity
Accounts payable	19,706		11,675
Accrued expenses and other	7,410		4,171
Deferred revenue, current	123		499
Current maturities of long-term debt	96		79
Total current liabilities	27,335		16,424
Revolving credit facility	9,202		3,908
Long-term debt, less current maturities	81		105
Deferred revenue, long-term	791		940
Other long-term liabilities	642		524
Total liabilities	38,051		21,901
Commitments and contingencies (Note 13)
Shareholders’ equity:
Preferred stock, $0.01 par value: Shares authorized: 30,000,000 shares at March 31, 2019 and 2018; no shares issued and outstanding at March 31, 2019 and 2018			0
Common stock, no par value: Shares authorized: 200,000,000 at March 31, 2019 and 2018; shares issued: 39,037,969 and 38,384,575 at March 31, 2019 and 2018; shares outstanding: 29,600,158 and 28,953,183 at March 31, 2019 and 2018			0
Additional paid-in capital	155,828		155,003
Treasury stock: 9,437,811 and 9,431,392 common shares at March 31, 2019 and 2018	(36,091)		(36,085)
Retained deficit	(101,767)		(95,494)
Total shareholders’ equity	17,970		23,424	$ 35,450	$ 45,983
Total liabilities and shareholders’ equity	56,021		45,325
ASC 606 | Adjustments
Assets
Accounts receivable, net	(67)
Revenue earned but not billed	(3,746)
Inventories, net	(351)
Deferred contract costs	396
Prepaid expenses and other current assets	3,419
Total current assets	(349)
Total assets	(349)
Liabilities and Shareholders’ Equity
Accounts payable	987
Accrued expenses and other	(1,193)
Deferred revenue, current	51
Total current liabilities	(155)
Deferred revenue, long-term	104
Other long-term liabilities	(104)
Total liabilities	(155)
Commitments and contingencies (Note 13)
Shareholders’ equity:
Preferred stock, $0.01 par value: Shares authorized: 30,000,000 shares at March 31, 2019 and 2018; no shares issued and outstanding at March 31, 2019 and 2018
Retained deficit	(194)
Total shareholders’ equity	(194)
Total liabilities and shareholders’ equity	(349)
ASC 606 | Balances without application of ASC 606
Assets
Cash and cash equivalents	8,729		$ 9,424
Accounts receivable, net	14,737
Inventories, net	13,052
Deferred contract costs	396
Prepaid expenses and other current assets	4,114
Total current assets	41,028
Property and equipment, net	12,010
Other intangible assets, net	2,469
Other long-term assets	165
Total assets	55,672
Liabilities and Shareholders’ Equity
Accounts payable	20,693
Accrued expenses and other	6,217
Deferred revenue, current	174
Current maturities of long-term debt	96
Total current liabilities	27,180
Revolving credit facility	9,202
Long-term debt, less current maturities	81
Deferred revenue, long-term	895
Other long-term liabilities	538
Total liabilities	37,896
Commitments and contingencies (Note 13)
Shareholders’ equity:
Preferred stock, $0.01 par value: Shares authorized: 30,000,000 shares at March 31, 2019 and 2018; no shares issued and outstanding at March 31, 2019 and 2018
Additional paid-in capital	155,828
Treasury stock: 9,437,811 and 9,431,392 common shares at March 31, 2019 and 2018	(36,091)
Retained deficit	(101,961)
Total shareholders’ equity	17,776
Total liabilities and shareholders’ equity	$ 55,672