Note 6 - Fair Value Measurements (Details) - Summary of Activity for Metro Bonds (Metropolitan District Bond Securities [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Metropolitan District Bond Securities [Member]
Note 6 - Fair Value Measurements (Details) - Summary of Activity for Metro Bonds [Line Items]
Balance at beginning of period	$ 14,291	$ 13,835	$ 12,729	$ 5,818
Increase in fair value (recorded in other comprehensive income)	798		1,757	7,354
Change due to accretion of principal	290	332	893	995
Balance at end of period	$ 15,379	$ 14,167	$ 15,379	$ 14,167