CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net loss	$ (51)	$ (2,452)
Adjustments to reconcile net loss to net cash provided by (used for) operating activities:
Depreciation and amortization	1,965	2,605
Provisions for contracts, inventory and accounts receivable reserves	(80)	(270)
Amortization of bond premium	63	540
Stock compensation expense	1,044	1,770
Other	202
Changes in assets and liabilities:
Accounts receivable	1,326	4,878
Unbilled costs and fees	(1,630)	(3,272)
Inventories	2,659	(11,534)
Prepaid expenses and other assets	2,111	(5,436)
Accounts payable	(2,453)	(6,762)
Accrued income taxes		(2,338)
Customer deposits	(2,399)	5,433
Deferred revenue	3,623	(1,847)
Accrued expenses and other liabilities	(3,221)	(7,274)
Net cash provided by (used for) operating activities	3,159	(25,959)
Cash flows from investing activities:
Purchases of short-term investments		(29,212)
Proceeds from sales and maturities of short-term investments	16,780	40,933
Purchases of property and equipment, net	(573)	(943)
Net cash provided by investing activities	16,207	10,778
Cash flows from financing activities:
Decrease in restricted cash	574	726
Proceeds from exercise of stock options		888
Repurchase of shares of common stock	(2,263)
Repayment of leasehold financing liability		(754)
Payment of common stock dividend	(7,219)	(7,993)
Net cash used for financing activities	(8,908)	(7,133)
Net increase (decrease) in cash and cash equivalents	10,458	(22,314)
Cash and cash equivalents at beginning of period	68,835	62,143
Cash and cash equivalents at end of period	$ 79,293	$ 39,829