Note 10 - Accumulated Other Comprehensive Income (Loss) - Activity in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Beginning balance	$ 377,000	$ 376,000	$ 314,000	$ 294,000	$ 376,000	$ 294,000
Other comprehensive income (loss), before reclassifications and income taxes	859,000	636,000	462,000	529,000
Amounts reclassified from accumulated other comprehensive income (loss), before income taxes	(636,000)	(635,000)	(529,000)	(496,000)
Income tax expense (benefit)	(91,000)		27,000	(13,000)
Total other comprehensive income	132,000	1,000	(40,000)	20,000
Ending balance	509,000	377,000	274,000	314,000	509,000	274,000
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Beginning balance	543,000	(124,000)	266,000	(509,000)	(124,000)	(509,000)
Other comprehensive income (loss), before reclassifications and income taxes	2,327,000	1,127,000	(2,698,000)	1,495,000
Amounts reclassified from accumulated other comprehensive income (loss), before income taxes	(84,000)		(48,000)	(186,000)
Income tax expense (benefit)	(914,000)	(460,000)	1,120,000	(534,000)
Total other comprehensive income	1,329,000	667,000	(1,626,000)	775,000
Ending balance	1,872,000	543,000	(1,360,000)	266,000	1,872,000	(1,360,000)
Beginning balance	920,000	252,000	580,000	(215,000)	252,000	(215,000)
Other comprehensive income (loss), before reclassifications and income taxes	3,186,000	1,763,000	(2,236,000)	2,024,000
Amounts reclassified from accumulated other comprehensive income (loss), before income taxes	(720,000)	(635,000)	(577,000)	(682,000)
Income tax expense (benefit)	(1,005,000)	(460,000)	1,147,000	(547,000)	(1,465,000)	600,000
Total other comprehensive income	1,461,000	668,000	(1,666,000)	795,000	2,129,000	(871,000)
Ending balance	$ 2,381,000	$ 920,000	$ (1,086,000)	$ 580,000	$ 2,381,000	$ (1,086,000)