Note 11 - Medical and Life Insurance Benefits - Retired Employees (Details) - Post Retirement Medical and Life Insurance Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Change in Benefit Obligations [Member]
Benefit obligation at beginning of year	$ 5,867	$ 10,964	$ 14,230
Service cost	113	225	484
Interest cost	$ 244	396	$ 518
Plan amendments		(5,730)
Benefits paid	$ (647)	(429)	$ (351)
Actuarial (gain) loss	1,034	441	(3,917)
Benefit obligation at end of year	6,611	5,867	10,964
Change in Plan Assets [Member]
Benefits paid	$ (647)	$ (429)	$ (351)
Fair value of plan assets at beginning of year
Employer contributions	$ 647	$ 429	$ 351
Fair value of plan assets at end of year
Amounts Recongnized in Balance Sheet [Member]
Current liability	$ (441)	$ (379)	$ (536)
Noncurrent liability	(6,170)	(5,488)	(10,428)
Net amount recognized in balance sheet	(6,611)	(5,867)	(10,964)
Components of Net Periodic Benefit Cost [Member]
Service cost	113	225	484
Interest cost	244	396	518
Amortization of prior service cost	$ (799)	(771)	(743)
Recognized actuarial loss		(1)	111
Net periodic benefit cost	$ (442)	$ (151)	$ 370
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.49%	4.29%	4.96%
Rate of compensation increase	2.64%	2.64%	2.64%
Net amount recognized in balance sheet	$ (6,611)	$ (5,867)	$ (10,964)
Discount rate	4.29%	4.96%	3.92%
Rate of compensation increase	2.64%	2.64%	2.64%
Prior service credit	$ 5,305	$ 6,104	$ 1,145
Accumulated loss	(850)	185	627
Amounts not yet recognized as a component of net periodic benefit cost	4,455	6,289	1,772
Accumulated net periodic benefit cost in excess of contributions	(11,066)	(12,156)	(12,736)
Prior service credit	781	$ 799	$ 502
Recognized actuarial loss	(15)
	$ 766	$ 799	$ 502
Healthcare cost trend rate assumed for next year	8.50%	8.30%	7.80%
Rate to which the cost trend rate gradually declines	4.50%	4.50%	4.50%
Year that the rate reaches the rate at which it is assumed to remain	2026	2026	2026