Note 9 - Pension and Other Postretirement Benefit Plans (Details) - Components of net expense for pension and other postretirement benefit plans: (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Employee Pension Plan [Member]
Note 9 - Pension and Other Postretirement Benefit Plans (Details) - Components of net expense for pension and other postretirement benefit plans: [Line Items]
Interest cost	$ 207	$ 220	$ 414	$ 440
Amortization of unrecognized (gain) loss	306	263	612	526
Expected return on plan assets	(315)	(310)	(630)	(620)
Net expense	198	173	396	346
Outside Director Pension Plan [Member]
Note 9 - Pension and Other Postretirement Benefit Plans (Details) - Components of net expense for pension and other postretirement benefit plans: [Line Items]
Service cost	21	20	42	40
Interest cost	24	28	48	56
Amortization of unrecognized (gain) loss	(9)	(7)	(18)	(14)
Amortization of past service liability (credit)	9	9	18	18
Net expense	45	50	90	100
Other Postretirement Benefit Plans [Member]
Note 9 - Pension and Other Postretirement Benefit Plans (Details) - Components of net expense for pension and other postretirement benefit plans: [Line Items]
Service cost	112	100	224	200
Interest cost	55	54	110	108
Amortization of unrecognized (gain) loss	12	10	24	20
Amortization of past service liability (credit)	(20)	(21)	(40)	(42)
Net expense	$ 159	$ 143	$ 318	$ 286