SELECTED QUARTERLY DATA (UNAUDITED) (Summary Of Selected Quarterly Data) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income	$ 44,161	$ 42,589	$ 40,821	$ 38,127	$ 36,307	$ 35,079	$ 34,355	$ 33,210	$ 165,698	$ 138,951	$ 122,539
Interest expense	8,769	7,969	7,002	6,066	5,400	5,360	5,082	4,628	29,806	20,470	16,612
Net interest income	35,392	34,620	33,819	32,061	30,907	29,719	29,273	28,582	135,892	118,481	105,927
Provision for loan losses	1,850	450	500	200	1,150	0	0	0	3,000	1,150	0
Net interest income after provision	33,542	34,170	33,319	31,861	29,757	29,719	29,273	28,582	132,892	117,331	105,927
Noninterest income	9,462	9,497	8,791	8,259	8,736	9,018	8,067	7,043
Noninterest expense	19,598	20,269	19,352	20,048	18,389	18,759	18,446	17,384	79,267	72,978	68,206
Income tax expense	11,779	7,573	7,394	5,558	6,582	6,498	6,091	5,962	32,304	25,133	22,833
Net income	$ 11,627	$ 15,825	$ 15,364	$ 14,514	$ 13,522	$ 13,480	$ 12,803	$ 12,279	$ 57,330	$ 52,084	$ 46,367
Basic earnings per common share	$ 0.46	$ 0.63	$ 0.61	$ 0.58	$ 0.54	$ 0.54	$ 0.51	$ 0.49	$ 2.28	$ 2.08	$ 1.86
Diluted earnings per common share	$ 0.45	$ 0.62	$ 0.6	$ 0.57	$ 0.53	$ 0.53	$ 0.5	$ 0.48	$ 2.23	$ 2.05	$ 1.84