Earnings Per Share (Schedule Of Earnings Per Share, Basic And Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator
Net income	$ 26,195	$ 17,048	$ 33,193	$ 20,019	$ 17,195	$ 9,470	$ 14,831	$ 8,799	$ 96,455	$ 50,295	$ 49,540
Less: Undistributed earnings allocated to participating securities									(59)	(384)	(1,050)
Net income allocable to common stockholders									$ 96,396	$ 49,911	$ 48,490
Denominator
Weighted average common shares outstanding - basic									30,084,913	24,280,871	20,679,189
Dilutive effect of restricted stock units									306,433	274,638	112,748
Weighted average common shares outstanding - diluted									30,391,346	24,555,509	20,791,937
Earnings per share:
Basic	$ 0.85	$ 0.56	$ 1.11	$ 0.68	$ 0.61	$ 0.37	$ 0.67	$ 0.40	$ 3.20	$ 2.06	$ 2.34
Diluted	$ 0.85	$ 0.56	$ 1.10	$ 0.67	$ 0.60	$ 0.37	$ 0.66	$ 0.40	$ 3.17	$ 2.03	$ 2.33