CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Mar. 31, 2014
Current assets:
Cash and cash equivalents	$ 39,829	$ 62,143
Restricted cash and investments	13,474	14,603
Short-term investments, at fair value	76,359	88,649
Accounts receivable, net of allowances of $343 and $323 at September 30, 2014 and March 31, 2014, respectively	29,419	34,317
Unbilled costs and fees	5,763	2,491
Inventories, net	45,200	32,935
Prepaid expenses and other current assets	10,441	5,459
Deferred income taxes	4,775	4,775
Total current assets	225,260	245,372
Building, equipment and leasehold improvements, net	10,866	12,969
Restricted cash and investments	716	313
Deferred income taxes	6,318	6,318
Other assets, net	993	539
Total assets	244,153	265,511
Current liabilities:
Accounts payable	3,856	10,618
Accrued salaries and benefits	8,308	10,805
Accrued warranty costs	186	404
Accrued income taxes		2,338
Deferred revenue	11,360	10,934
Customer deposits	22,022	16,589
Current portion of lease financing liability	1,521	1,511
Other current liabilities	4,975	9,292
Total current liabilities	52,228	62,491
Lease financing liability, net of current portion	640	1,404
Deferred revenue	1,668	3,941
Other long-term liabilities	38	280
Total liabilities	54,574	68,116
Stockholders' equity:
Preferred stock, no par value, 100,000 shares authorized; no shares issued
Common stock, $0.66 2/3 par value, 20,000,000 shares authorized 7,930,618 and 7,884,015 shares issued and outstanding at September 30, 2014 and March 31, 2014, respectively	5,287	5,255
Capital in excess of par value	37,854	35,236
Accumulated other comprehensive income (loss), net	(16)	13
Retained earnings	146,454	156,891
Total stockholders' equity	189,579	197,395
Total liabilities and stockholders' equity	$ 244,153	$ 265,511