CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (10,337)	$ 163	$ (4,515)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Allowance for doubtful accounts and other	(17)	39	(41)
Provision for excess and obsolete inventories	343	1,195	1,561
Non-cash lease expense	611
Depreciation and amortization	1,434	1,454	1,255
Stock-based compensation	2,566	2,266	2,070
Amortization of premium on investments		(36)	73
Changes in assets and liabilities:
Accounts receivable	1,026	(2,099)	1,111
Inventory	1,060	(1,333)	2,103
Prepaid expenses and other assets	(431)	(144)	117
Accounts payable	(680)	48	189
Accrued expenses and other liabilities	(256)	1,453	(2,858)
Net cash provided by (used in) operating activities	(4,681)	3,006	1,065
Cash flows from investing activities:
Purchase of investments	(18,116)	(20,307)	(13,243)
Maturities of short-term investments	27,418	18,173	16,140
Decrease in MikaMonu escrow deposit	1,000	750	1,234
Purchases of property and equipment	(331)	(2,090)	(1,320)
Net cash provided by (used in) investing activities	9,971	(3,474)	2,811
Cash flows from financing activities:
Payment of contingent consideration		(720)
Payment of MikaMonu escrow deposit	(428)	(364)	(862)
Repurchase of common stock		(103)
Proceeds from issuance of common stock under employee stock plans	4,149	3,909	3,491
Net cash provided by financing activities	3,721	2,722	2,629
Net increase in cash and cash equivalents	9,011	2,254	6,505
Cash and cash equivalents at beginning of the period	42,495	40,241	33,736
Cash and cash equivalents at end of the period	51,506	42,495	40,241
Non-cash financing activities:
Purchases of property and equipment through accounts payable and accruals	19	31	105
Supplemental cash flow information:
Net cash paid for income taxes	$ 345	$ 11	$ 39