Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Cash flows from operating activities
Net income (loss)	$ 2,514	$ (5,209)	$ 2,203
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Deferred income taxes	286	273	1,014
Depreciation of property and equipment	907	1,030	986
Stock-based compensation	331	382	375
Impairment of goodwill		7,970
Amortization of intangible assets	504	222	159
Change in fair value of contingent acquisition consideration	(619)	55
Loss on disposal of equipment	1	9
Gain on sale of Vehicle Sensors	(1,180)
Changes in operating assets and liabilities, net of effects of acquisitions and sale of Vehicle Sensors:
Accounts receivable	(1,826)	1,052	1,137
Net costs and estimated earnings in excess of billings	(902)	(501)	917
Inventories	79	(953)	2,954
Prepaid expenses and other assets	284	211	(350)
Accounts payable and accrued expenses	289	805	(2,911)
Net cash provided by operating activities	668	5,346	6,484
Cash flows from investing activities
Purchases of property and equipment	(337)	(414)	(294)
Capitalized software	(138)
Net cash paid for acquisitions	(969)	(1,116)	(300)
Net proceeds from sale of Vehicle Sensors	11,446
Net cash provided by (used in) investing activities	10,002	(1,530)	(594)
Cash flows from financing activities
Payments on long-term debt	(2,330)	(2,354)	(2,750)
Borrowings on long-term debt			750
Repurchases of common stock	(754)
Deferred payment for prior business combinations	(788)	(106)
Proceeds from stock option exercises	85	57	143
Net cash used in financing activities	(3,787)	(2,403)	(1,857)
Increase in cash and cash equivalents	6,883	1,413	4,033
Cash and cash equivalents at beginning of year	11,818	10,405	6,372
Cash and cash equivalents at end of year	18,701	11,818	10,405
Cash paid during the year for:
Interest	111	200	306
Income taxes	439	455	159
Supplemental schedule of non-cash investing and financing activities:
Liabilities incurred for business combinations	971	2,610	218
Issuance of common stock for vested restricted stock units	5
Fair value of common stock issued in settlement of liabilities			$ 31