Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (32,776)	$ (27,373)	$ (23,139)
Adjustments to reconcile net loss to net cash used in operations:
Depreciation and amortization	11,459	7,519	7,972
Stock-based compensation expense	2,692	2,892	3,248
Impairment of minority interest investments	0	0	746
Provision for excess and obsolete inventory	434	1,615	2,713
(Recovery)/Write-off prepaid taxes	(82)	0	289
Gain on sale from minority interest investments	(1,167)	(325)	(3,092)
Loss from minority interest investments	0	0	356
Change in fair value of warrants and contingent consideration	(635)	(1,304)	228
Non-cash interest expense	19	156	359
Other non-cash items	793	(940)	1,462
Changes in operating asset and liability accounts:
Accounts receivable	1,145	11,143	(9,318)
Inventory	(2,423)	(815)	(782)
Prepaid expenses and other current assets	558	2,729	5,608
Accounts payable and accrued expenses	(2,956)	(7,938)	1,543
Deferred revenue	(1,888)	1,426	7,248
Net cash used in operating activities	(24,827)	(11,215)	(4,559)
Cash flows from investing activities:
Purchase of property, plant and equipment	(2,534)	(656)	(1,201)
Proceeds from the sale of property, plant and equipment	16,910	29	47
Change in restricted cash	795	431	2,669
Cash paid for acquisition, net of cash received	74	0	0
Proceeds from sale of minority interests	1,167	325	3,092
Change in other assets	(15)	63	266
Net cash provided by investing activities	16,397	192	4,873
Cash flows from financing activities:
Employee taxes paid related to net settlement of equity awards	(274)	(490)	(110)
Repayment of debt	(1,575)	(3,167)	(4,000)
Proceeds from ATM sales, net	0	2,527	0
Proceeds from public equity offering, net	16,952	0	22,282
Proceeds from exercise of employee stock options and ESPP	175	0	30
Net cash provided by (used in) financing activities	15,278	(1,130)	18,202
Effect of exchange rate changes on cash and cash equivalents	452	(393)	324
Net increase/(decrease) in cash and cash equivalents	7,300	(12,546)	18,840
Cash and cash equivalents at beginning of year	26,784	39,330	20,490
Cash and cash equivalents at end of year	34,084	26,784	39,330
Supplemental schedule of cash flow information:
Issuance of common stock in connection with the purchase of Infinia Technology Corporation	3,498	0	0
Cash paid for income taxes, net of refunds	1,576	992	1,723
Issuance of common stock to settle liabilities	350	399	377
Deferred gain on sale of 64 Jackson Road building	105	0	0
Cash paid for interest	$ 42	$ 280	$ 709