CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ 163	$ (4,515)	$ (115)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Allowance for sales returns, doubtful accounts and other	39	(41)	4
Provision for excess and obsolete inventories	1,195	1,561	588
Depreciation and amortization	1,454	1,255	1,532
Stock-based compensation	2,266	2,070	1,877
Amortization of premium (discount) on investments	(36)	73	74
Changes in assets and liabilities:
Accounts receivable	(2,099)	1,111	1,125
Inventory	(1,333)	2,103	(2,625)
Prepaid expenses and other assets	(144)	117	103
Accounts payable	48	189	(887)
Accrued expenses and other liabilities	1,453	(1,183)	911
Deferred revenue		(1,675)	(534)
Net cash provided by operating activities	3,006	1,065	2,053
Cash flows from investing activities:
Purchase of investments	(20,307)	(13,243)	(18,563)
Maturities of short-term investments	18,173	16,140	23,600
Decrease in MikaMonu escrow deposit	750	1,234
Purchases of property and equipment	(2,090)	(1,320)	(219)
Net cash provided by (used in) investing activities	(3,474)	2,811	4,818
Cash flows from financing activities:
Repurchase of common stock	(103)		(7,112)
Payment of MikaMonu escrow deposit	(364)	(862)
Payment of contingent consideration	(720)
Proceeds from issuance of common stock under employee stock plans	3,909	3,491	2,014
Net cash provided by (used in) financing activities	2,722	2,629	(5,098)
Net increase in cash and cash equivalents	2,254	6,505	1,773
Cash and cash equivalents at beginning of the period	40,241	33,736	31,963
Cash and cash equivalents at end of the period	42,495	40,241	33,736
Non-cash financing activities:
Purchases of property and equipment through accounts payable and accruals	31	105
Supplemental cash flow information:
Net cash paid for income taxes	$ 11	$ 39	$ 1,339