Note 8 - Stock-Based Compensation (Details) - Phantom Stock Plan: (Phantom Share Units (PSUs) [Member], USD $)	9 Months Ended
	Sep. 30, 2013
Phantom Share Units (PSUs) [Member]
Note 8 - Stock-Based Compensation (Details) - Phantom Stock Plan: [Line Items]
Outstanding at December 31, 2012	50,067
Outstanding at December 31, 2012 (in Dollars per share)	$ 15.34
Granted	9,467
Granted (in Dollars per share)	$ 15.74
Distributions	(500)
Distributions (in Dollars per share)	$ 16.26
Outstanding at September 30, 2013	59,034
Outstanding at September 30, 2013 (in Dollars per share)	$ 18.45
Vested at September 30, 2013	58,742
Vested at September 30, 2013 (in Dollars per share)	$ 18.45