Note 15 - Benefit Plans (Details) - Combined Change in Benefit Obligation Defined Benefit Pension Plan Assets and Funded Status (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in benefit obligation
Interest cost	$ 892	$ 848	$ 958
Change in Pension Plan assets
Fair value of Pension Plan assets, beginning of period	16,798
Fair value of Pension Plan assets, end of period	17,429	16,798
Underfunded status	(3,009)	(1,324)	(3,967)
Net actuarial loss	(13,975)	(11,235)	(12,627)
Income tax benefit	(4,891)	(3,932)	(4,419)
Accumulated other comprehensive loss impact	(9,084)	(7,303)	(8,208)
Change in Benefit Obligation [Member]
Change in benefit obligation
Benefit obligation, beginning of period	18,122	18,507	19,786
Benefit obligation, end of period	20,438	18,122	18,507
Interest cost	892	848	958
Net actuarial loss	4,110	80	668
Benefits paid	(2,686)	(1,313)	(2,905)
Change in Plan Assets [Member]
Change in benefit obligation
Benefits paid	(2,686)	(1,313)	(2,905)
Change in Pension Plan assets
Fair value of Pension Plan assets, beginning of period	16,798	14,540	13,663
Fair value of Pension Plan assets, end of period	17,429	16,798	14,540
Return on Pension Plan assets	1,717	1,678	2,182
Employer contribution	$ 1,600	$ 1,893	$ 1,600