Note 14 - Employee Savings and Retirement Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Plan 401(k) [Member]
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	100.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 606	$ 616	$ 615
Westcode Semiconductor Group Personal Pension [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	7.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	100.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 241	$ 278	$ 287
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	4.50%