Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Unrealized gain (loss) on interest rate derivative instruments, net of deferred taxes of $0, ($550) and ($423)	$ 0	$ (550)	$ (423)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	(13)	0	0
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion, Tax	$ 130	$ 50	$ 0