CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011
Current assets:
Cash and cash equivalents	$ 29,495	$ 60,144
Restricted cash and investments	12,846	20,398
Short-term investments, at fair value	174,052	110,141
Accounts receivable, net of allowances of $353 and $334 at December 31, 2011 and March 31, 2011, respectively	27,044	37,180
Unbilled costs and fees	3,585	17,082
Inventories, net	45,858	46,922
Prepaid expenses and other current assets	8,969	6,698
Deferred income taxes	2,420	3,469
Total current assets	304,269	302,034
Building, equipment and leasehold improvements, net	18,041	18,559
Restricted cash and investments	784	9,062
Deferred income taxes	6,297	6,779
Other assets, net	81	140
Total assets	329,472	336,574
Current liabilities:
Accounts payable	8,575	9,378
Accrued salaries and benefits	9,020	15,988
Accrued warranty costs	572	1,225
Accrued income taxes	1,884	1,936
Deferred revenue	15,668	16,924
Customer deposits	17,401	9,193
Current portion of lease financing liability	1,335	1,321
Other current liabilities	7,399	5,460
Total current liabilities	61,854	61,425
Lease financing liability, net of current portion	4,751	5,755
Deferred revenue	2,622	3,288
Other long term liabilities	21	26
Total liabilities	69,248	70,494
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 8,915,469 and 9,169,965 shares issued and outstanding at December 31, 2011 and March 31, 2011, respectively	5,943	6,113
Capital in excess of par value	94,300	110,087
Accumulated other comprehensive income, net	7	21
Retained earnings	159,974	149,859
Total stockholders' equity	260,224	266,080
Total liabilities and stockholders' equity	$ 329,472	$ 336,574