Note 11 - Stock-Based Compensation (Details) - Options Outstanding and Exercisable, by Exercise Range (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Sep. 30, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable Range of Exercise Price Minimum	$ 3.70
Options Outstanding and Exercisable Range of Exercise Price Maximum	$ 34.00
Options Outstanding, Number of Shares (in Shares)	165
Options Outstanding, Weighted-Average Remaining Contractual Life	5 years 339 days
Options Vested and Exercisable, Number of Shares (in Shares)	89
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 8.28
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable Range of Exercise Price Minimum	$ 3.70
Options Outstanding and Exercisable Range of Exercise Price Maximum	$ 5.20
Options Outstanding, Number of Shares (in Shares)	35
Options Outstanding, Weighted-Average Remaining Contractual Life	3 years 328 days
Options Vested and Exercisable, Number of Shares (in Shares)	23
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 4.71
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable Range of Exercise Price Minimum	$ 5.21
Options Outstanding and Exercisable Range of Exercise Price Maximum	$ 5.39
Options Outstanding, Number of Shares (in Shares)	37
Options Outstanding, Weighted-Average Remaining Contractual Life	7 years 178 days
Options Vested and Exercisable, Number of Shares (in Shares)	23
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 5.32
Range Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable Range of Exercise Price Minimum	$ 5.40
Options Outstanding and Exercisable Range of Exercise Price Maximum	$ 5.60
Options Outstanding, Number of Shares (in Shares)	2
Options Outstanding, Weighted-Average Remaining Contractual Life	219 days
Options Vested and Exercisable, Number of Shares (in Shares)	2
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 5.59
Range Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable Range of Exercise Price Minimum	$ 5.61
Options Outstanding and Exercisable Range of Exercise Price Maximum	$ 5.72
Options Outstanding, Number of Shares (in Shares)	50
Options Outstanding, Weighted-Average Remaining Contractual Life	9 years 317 days
Range Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable Range of Exercise Price Minimum	$ 5.73
Options Outstanding and Exercisable Range of Exercise Price Maximum	$ 34.00
Options Outstanding, Number of Shares (in Shares)	41
Options Outstanding, Weighted-Average Remaining Contractual Life	1 year 255 days
Options Vested and Exercisable, Number of Shares (in Shares)	41
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 11.97