Segment Information (Summary Of Financial Information By Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Interest income	$ 235,205	$ 233,802	$ 231,788	$ 229,071	$ 242,151	$ 239,523	$ 224,967	$ 115,880	$ 929,866	$ 822,521	$ 442,846
Interest expense	15,371	14,587	14,322	13,952	14,136	13,807	12,708	8,042	58,232	48,693	37,881
Net interest income	219,834	219,215	217,466	215,119	228,015	225,716	212,259	107,838	871,634	773,828	404,965
Provision for loan and lease losses	4,545	8,153	11,254	12,637	5,241	14,333	14,696	5,971	36,589	40,241	10,716
Non-interest income	69,345	61,372	81,102	63,905	50,305	62,165	45,466	23,238	275,724	181,174	122,895
Non-interest expense	185,911	183,194	201,918	192,619	190,856	182,558	214,131	96,518	763,642	684,063	364,661
Income before income taxes	98,723	89,240	85,396	73,768	82,223	90,990	28,898	28,587	347,127	230,698	152,483
Provision for income taxes	35,704	31,633	30,612	26,639	29,641	32,107	11,356	9,936	124,588	83,040	54,192
Net income	63,019	$ 57,607	$ 54,784	$ 47,129	52,582	$ 58,883	$ 17,542	$ 18,651	222,539	147,658	98,291
Total assets	23,387,205				22,609,903				23,387,205	22,609,903	11,632,603
Total loans and leases	16,847,360				15,327,732				16,847,360	15,327,732	7,728,166
Total deposits	17,707,189				16,892,099				17,707,189	16,892,099	9,117,660
Community Banking [Member]
Segment Reporting Information [Line Items]
Interest income									823,885	755,374	420,854
Interest expense									49,081	43,077	35,367
Net interest income									774,804	712,297	385,487
Provision for loan and lease losses									32,808	40,241	10,716
Non-interest income									130,877	93,177	43,556
Non-interest expense									646,492	615,275	325,743
Income before income taxes									226,381	149,958	92,584
Provision for income taxes									81,252	54,427	30,232
Net income									145,129	95,531	62,352
Total assets	20,195,322				20,095,189				20,195,322	20,095,189	10,945,541
Total loans and leases	14,164,743				13,181,463				14,164,743	13,181,463	7,196,137
Total deposits	17,689,815				16,850,682				17,689,815	16,850,682	9,090,959
Home Lending [Member]
Segment Reporting Information [Line Items]
Interest income									105,981	67,147	21,992
Interest expense									9,151	5,616	2,514
Net interest income									96,830	61,531	19,478
Provision for loan and lease losses									3,781	0	0
Non-interest income									144,847	87,997	79,339
Non-interest expense									117,150	68,788	38,918
Income before income taxes									120,746	80,740	59,899
Provision for income taxes									43,336	28,613	23,960
Net income									77,410	52,127	35,939
Total assets	3,191,883				2,514,714				3,191,883	2,514,714	687,062
Total loans and leases	2,682,617				2,146,269				2,682,617	2,146,269	532,029
Total deposits	$ 17,374				$ 41,417				$ 17,374	$ 41,417	$ 26,701