Business Combinations (Schedule Of Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pro Forma Financial Information [Abstract]
Revenue	$ 416,223	$ 347,153	$ 1,142,371	$ 941,953
Income before taxes expense	24,604	22,303	69,950	55,052
Tax expense	(10,731)	(6,270)	(23,878)	(16,476)
Net income	13,873	16,033	46,072	38,576
Less: Undistributed earnings allocated to participating securities	(72)	(242)	(352)	(734)
Numerator for basic and diluted pro forma EPS	$ 13,801	$ 15,791	$ 45,720	$ 37,842
Pro forma weighted average shares-basic	27,034,192	24,849,375	26,342,362	24,819,536
Pro forma weighted average shares-diluted	27,314,776	24,997,920	26,579,292	24,907,783
Pro forma basic EPS	$ 0.51	$ 0.64	$ 1.74	$ 1.52
Pro forma diluted EPS	$ 0.51	$ 0.63	$ 1.72	$ 1.52