Note 8 - Stock-Based Compensation (Detail) - Phantom Stock Plan: (USD $)	3 Months Ended
	Mar. 31, 2013
Shares	50,067
Fair Value (in Dollars per share)	$ 15.34
Vested at March 31, 2013	58,311
Vested at March 31, 2013 (in Dollars per share)	$ 16.94
Granted	8,589
Granted (in Dollars per share)	$ 15.57
Distributions	(13)
Distributions (in Dollars per share)	$ 15.84
Shares	58,643
Fair Value (in Dollars per share)	$ 16.94