CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Current assets:
Cash and cash equivalents	$ 58,874	$ 91,332
Short-term investments	89,877	51,561
Receivables (net of allowances of $400 at September 30, 2017 and $272 at March 31, 2017)	40,714	40,568
Inventories	39,050	39,010
Prepaid expenses and other current assets	4,831	4,997
Net deferred tax assets, current	0	5,644
Current assets of discontinued operations	19	66
Total current assets	233,365	233,178
Long-term investments	28,951	22,171
Investment in unconsolidated affiliates	2,778	2,850
Property and equipment, net	34,384	34,260
Intangible assets, net	1,094	1,171
Net deferred tax assets, non-current	10,472	4,392
Other assets	8,904	7,624
Total assets	319,948	305,646
Current liabilities:
Accounts payable	8,393	7,517
Accrued payroll and related expenses	10,101	9,606
Accrued taxes	1,489	2,151
Current liabilities of discontinued operations	29	85
Other accrued liabilities	13,811	11,006
Deferred revenue	1,043	1,415
Warranty reserve	1,934	1,663
Total current liabilities	36,800	33,443
Non-current liabilities:
Deferred revenue	1,290	1,460
Warranty reserve	2,825	2,695
Net deferred tax liabilities	219	234
Notes payable, less current portion	227	278
Other non-current liabilities	1,498	1,312
Total non-current liabilities	6,059	5,979
Total liabilities	42,859	39,422
Commitments and contingencies (Note 13)
Shareholders' equity:
Preferred stock, no par value: 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, no par value: 35,000,000 shares authorized; 22,691,000 and 22,540,000 shares issued and outstanding at September 30, 2017 and March 31, 2017, respectively	140,235	135,932
Retained earnings	136,886	130,304
Accumulated other comprehensive loss	(32)	(12)
Total shareholders' equity	277,089	266,224
Total liabilities and shareholders' equity	$ 319,948	$ 305,646