Summary Of Quarterly Financial Information (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Total interest income	$ 79,897	$ 77,133	$ 76,087	$ 74,925	$ 78,307	$ 81,599	$ 82,268	$ 54,761	$ 308,042	$ 296,935	$ 248,504
Total interest expense	1,133	913	963	985	1,098	1,184	2,279	1,279	3,994	5,840	9,577
Net Interest Income	78,764	76,220	75,124	73,940	77,209	80,415	79,989	53,482	304,048	291,095	238,927
Provision (recapture) for loan and lease losses	1,708	980	2,117	1,922	(3,682)	3,313	288	(20)	6,727	(101)	39,367
Noninterest income (loss)	15,185	15,930	14,627	14,008	10,612	7,622	6,808	1,658	59,750	26,700	27,058
Noninterest expense	64,154	59,982	57,764	57,386	63,619	64,714	64,504	38,049	239,286	230,886	162,913
Income before income taxes	28,087	31,188	29,870	28,640	27,884	20,010	22,005	17,111	117,785	87,010	63,705
Income tax expense (benefit)	9,167	9,605	8,643	8,796	7,911	6,734	7,414	4,935	36,211	26,994	17,562
Net income (loss)	$ 18,920	$ 21,583	$ 21,227	$ 19,844	$ 19,973	$ 13,276	$ 14,591	$ 12,176	$ 81,574	$ 60,016	$ 46,143
Per Common Share
Earnings (basic)	$ 0.34	$ 0.41	$ 0.40	$ 0.38	$ 0.39	$ 0.26	$ 0.28	$ 0.31	$ 1.53	$ 1.24	$ 1.16
Earnings (diluted)	$ 0.34	$ 0.41	$ 0.40	$ 0.37	$ 0.38	$ 0.25	$ 0.28	$ 0.31	$ 1.52	$ 1.21	$ 1.16