Note 6 Balance Sheet Details (Property, Plant and Equipment) (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Property, Plant and Equipment [Abstract]
Property and Plant (Useful Life of 24 Years to 50 Years)	$ 34,271,000	$ 33,996,000
Equipment Owned (Useful Life of 1 to 14 Years)	107,378,000	97,104,000
Equipment Capital Leases (Useful Life of 4 Years)	41,931,000	40,010,000
Leasehold Improvements (Useful Life of up to 8 Years)	1,253,000	917,000
Property, Plant and Equipment, Gross	184,833,000	172,027,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(134,264,000)	(120,032,000)
Property, Plant and Equipment, Net	50,569,000	51,995,000
Depreciation Expense	$ 10,700,000	$ 10,200,000	$ 10,900,000
Property and Plant [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	50 years
Property and Plant [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	24 years
Equipment Owned [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	14 years
Equipment Owned [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	1 year
Equipment Capital Leases [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	4 years
Equipment Capital Leases [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	4 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	8 years