Note 6 - Balance Sheet Details - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Building and Building Improvements [Member]
Property, Plant and Equipment, Gross	$ 35,290	$ 33,328
Equipment [Member]
Property, Plant and Equipment, Gross	104,711	98,408
Assets Held under Capital Leases [Member]
Property, Plant and Equipment, Gross	34,607	33,222
Leasehold Improvements [Member]
Property, Plant and Equipment, Gross	1,304	1,304
Property, Plant and Equipment, Gross	175,912	166,262
Accumulated depreciation	(133,289)	(123,717)
Net property, plant and equipment	$ 42,623	$ 42,545	$ 50,569