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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator
Net income	$ 53,358	$ 27,024	$ 15,495	$ 17,117	$ 26,195	$ 17,048	$ 33,193	$ 20,019	$ 112,994	$ 96,455	$ 50,295
Less: Undistributed earnings allocated to participating securities										(59)	(384)
Net income allocable to common stockholders									$ 112,994	$ 96,396	$ 49,911
Denominator
Weighted average common shares outstanding - basic									30,886,382	30,084,913	24,280,871
Dilutive effect of restricted stock units									300,570	306,433	274,638
Weighted average common shares outstanding - diluted									31,186,952	30,391,346	24,555,509
Earnings per share:
Basic	$ 1.65	$ 0.88	$ 0.51	$ 0.57	$ 0.85	$ 0.56	$ 1.11	$ 0.68	$ 3.66	$ 3.20	$ 2.06
Diluted	$ 1.63	$ 0.87	$ 0.51	$ 0.56	$ 0.85	$ 0.56	$ 1.10	$ 0.67	$ 3.62	$ 3.17	$ 2.03